; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -loop-deletion -S | FileCheck %s ; RUN: opt < %s -passes='loop(loop-deletion)' -S | FileCheck %s ; The idea is that we know that %is.positive is true on the 1st iteration, ; it means that we can evaluate %merge.phi = %sub on the 1st iteration, ; and therefore prove that %sum.next = %sum + %sub = %sum + %limit - %sum = %limit, ; and predicate is false. ; TODO: We can break the backedge here. define i32 @test_ne(i32 %limit) { ; CHECK-LABEL: @test_ne( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_slt(i32 %limit) { ; CHECK-LABEL: @test_slt( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp slt i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp slt i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_ult(i32 %limit) { ; CHECK-LABEL: @test_ult( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ult i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ult i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_sgt(i32 %limit) { ; CHECK-LABEL: @test_sgt( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp sgt i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp sgt i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_ugt(i32 %limit) { ; CHECK-LABEL: @test_ugt( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ugt i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ugt i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_multiple_pred(i32 %limit) { ; CHECK-LABEL: @test_multiple_pred( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: switch i32 [[LIMIT]], label [[FAILURE_LOOPEXIT:%.*]] [ ; CHECK-NEXT: i32 100, label [[BACKEDGE]] ; CHECK-NEXT: i32 200, label [[BACKEDGE]] ; CHECK-NEXT: ] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[IF_TRUE]] ], [ [[SUB]], [[IF_TRUE]] ] ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure.loopexit: ; CHECK-NEXT: br label [[FAILURE]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: switch i32 %limit, label %failure [ i32 100, label %backedge i32 200, label %backedge ] if.false: ; preds = %loop br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %if.true ], [ %sub, %if.true ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_ne_const() { ; CHECK-LABEL: @test_ne_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_slt_const() { ; CHECK-LABEL: @test_slt_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp slt i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp slt i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_ult_const() { ; CHECK-LABEL: @test_ult_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ult i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ult i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_sgt_const() { ; CHECK-LABEL: @test_sgt_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp sgt i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp sgt i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_ugt_const() { ; CHECK-LABEL: @test_ugt_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ugt i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ugt i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_multiple_pred_const() { ; CHECK-LABEL: @test_multiple_pred_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: switch i32 4, label [[FAILURE:%.*]] [ ; CHECK-NEXT: i32 100, label [[BACKEDGE:%.*]] ; CHECK-NEXT: i32 200, label [[BACKEDGE]] ; CHECK-NEXT: ] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[IF_TRUE]] ], [ [[SUB]], [[IF_TRUE]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: switch i32 4, label %failure [ i32 100, label %backedge i32 200, label %backedge ] if.false: ; preds = %loop br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %if.true ], [ %sub, %if.true ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_multiple_pred_2(i1 %cond, i1 %cond2) { ; CHECK-LABEL: @test_multiple_pred_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE_1:%.*]], label [[IF_TRUE_2:%.*]] ; CHECK: if.true.1: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: if.true.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false: ; CHECK-NEXT: br i1 [[COND2:%.*]], label [[IF_FALSE_1:%.*]], label [[IF_FALSE_2:%.*]] ; CHECK: if.false.1: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE_1]] ], [ 0, [[IF_FALSE_2]] ], [ [[SUB]], [[IF_TRUE_1]] ], [ [[SUB]], [[IF_TRUE_2]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: br i1 %cond, label %if.true.1, label %if.true.2 if.true.1: br label %backedge if.true.2: br label %backedge if.false: ; preds = %loop br i1 %cond2, label %if.false.1, label %if.false.2 if.false.1: br label %backedge if.false.2: br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false.1 ], [ 0, %if.false.2 ], [ %sub, %if.true.1 ], [ %sub, %if.true.2 ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_multiple_pred_undef_1(i1 %cond, i1 %cond2) { ; CHECK-LABEL: @test_multiple_pred_undef_1( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE_1:%.*]], label [[IF_TRUE_2:%.*]] ; CHECK: if.true.1: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: if.true.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false: ; CHECK-NEXT: br i1 [[COND2:%.*]], label [[IF_FALSE_1:%.*]], label [[IF_FALSE_2:%.*]] ; CHECK: if.false.1: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE_1]] ], [ 0, [[IF_FALSE_2]] ], [ [[SUB]], [[IF_TRUE_1]] ], [ undef, [[IF_TRUE_2]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: br i1 %cond, label %if.true.1, label %if.true.2 if.true.1: br label %backedge if.true.2: br label %backedge if.false: ; preds = %loop br i1 %cond2, label %if.false.1, label %if.false.2 if.false.1: br label %backedge if.false.2: br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false.1 ], [ 0, %if.false.2 ], [ %sub, %if.true.1 ], [ undef, %if.true.2 ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_multiple_pred_undef_2(i1 %cond, i1 %cond2) { ; CHECK-LABEL: @test_multiple_pred_undef_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE_1:%.*]], label [[IF_TRUE_2:%.*]] ; CHECK: if.true.1: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: if.true.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false: ; CHECK-NEXT: br i1 [[COND2:%.*]], label [[IF_FALSE_1:%.*]], label [[IF_FALSE_2:%.*]] ; CHECK: if.false.1: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE_1]] ], [ 0, [[IF_FALSE_2]] ], [ undef, [[IF_TRUE_1]] ], [ [[SUB]], [[IF_TRUE_2]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: br i1 %cond, label %if.true.1, label %if.true.2 if.true.1: br label %backedge if.true.2: br label %backedge if.false: ; preds = %loop br i1 %cond2, label %if.false.1, label %if.false.2 if.false.1: br label %backedge if.false.2: br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false.1 ], [ 0, %if.false.2 ], [ undef, %if.true.1 ], [ %sub, %if.true.2 ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_multiple_pred_undef_3(i1 %cond, i1 %cond2) { ; CHECK-LABEL: @test_multiple_pred_undef_3( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: br i1 [[IS_POSITIVE]], label [[IF_TRUE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.true: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_TRUE_1:%.*]], label [[IF_TRUE_2:%.*]] ; CHECK: if.true.1: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: if.true.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false: ; CHECK-NEXT: br i1 [[COND2:%.*]], label [[IF_FALSE_1:%.*]], label [[IF_FALSE_2:%.*]] ; CHECK: if.false.1: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: if.false.2: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE_1]] ], [ 0, [[IF_FALSE_2]] ], [ undef, [[IF_TRUE_1]] ], [ undef, [[IF_TRUE_2]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 br i1 %is.positive, label %if.true, label %if.false if.true: br i1 %cond, label %if.true.1, label %if.true.2 if.true.1: br label %backedge if.true.2: br label %backedge if.false: ; preds = %loop br i1 %cond2, label %if.false.1, label %if.false.2 if.false.1: br label %backedge if.false.2: br label %backedge backedge: %merge.phi = phi i32 [ 0, %if.false.1 ], [ 0, %if.false.2 ], [ undef, %if.true.1 ], [ undef, %if.true.2 ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa failure: unreachable } ; TODO: We can break the backedge here. define i32 @test_select(i32 %limit) { ; CHECK-LABEL: @test_select( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[LOOP_GUARD:%.*]] = icmp sgt i32 [[LIMIT:%.*]], 0 ; CHECK-NEXT: br i1 [[LOOP_GUARD]], label [[LOOP_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: loop.preheader: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ [[SUM_NEXT:%.*]], [[LOOP]] ], [ 0, [[LOOP_PREHEADER]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[LIMIT]], [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[IS_POSITIVE]], i32 [[SUB]], i32 0 ; CHECK-NEXT: [[SUM_NEXT]] = add i32 [[SUM]], [[SEL]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], [[LIMIT]] ; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[LOOP]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; entry: %loop_guard = icmp sgt i32 %limit, 0 br i1 %loop_guard, label %loop, label %failure loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %loop ] %sub = sub i32 %limit, %sum %is.positive = icmp sgt i32 %sub, 0 %sel = select i1 %is.positive, i32 %sub, i32 0 %sum.next = add i32 %sum, %sel %loop.cond = icmp ne i32 %sum.next, %limit br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %loop ] ret i32 %sum.next.lcssa failure: unreachable } define i32 @test_select_const(i32 %x) { ; CHECK-LABEL: @test_select_const( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: [[IS_POSITIVE:%.*]] = icmp sgt i32 [[SUB]], 0 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[IS_POSITIVE]], i32 [[SUB]], i32 [[X:%.*]] ; CHECK-NEXT: [[SEL_COND:%.*]] = icmp sgt i32 [[SEL]], 0 ; CHECK-NEXT: br i1 [[SEL_COND]], label [[BACKEDGE:%.*]], label [[IF_FALSE:%.*]] ; CHECK: if.false: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[IF_FALSE]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum %is.positive = icmp sgt i32 %sub, 0 %sel = select i1 %is.positive, i32 %sub, i32 %x %sel.cond = icmp sgt i32 %sel, 0 br i1 %sel.cond, label %backedge, label %if.false if.false: ; preds = %loop br label %backedge backedge: ; preds = %if.false, %loop %merge.phi = phi i32 [ 0, %if.false ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa } ; Switch tests ; Here switch will always jump to the default label define i32 @test_switch_ne_default() { ; CHECK-LABEL: @test_switch_ne_default( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: switch i32 [[SUB]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i32 0, label [[ONZERO:%.*]] ; CHECK-NEXT: i32 1, label [[ONONE:%.*]] ; CHECK-NEXT: i32 2, label [[ONTWO:%.*]] ; CHECK-NEXT: ] ; CHECK: default: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: onzero: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: onone: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: ontwo: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ [[SUB]], [[DEFAULT]] ], [ 0, [[ONZERO]] ], [ 1, [[ONONE]] ], [ 2, [[ONTWO]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum switch i32 %sub, label %default [ i32 0, label %onzero i32 1, label %onone i32 2, label %ontwo ] default: ; preds = %loop br label %backedge onzero: ; preds = %loop br label %backedge onone: ; preds = %loop br label %backedge ontwo: ; preds = %loop br label %backedge backedge: ; preds = %ontwo, %onone, %onzero, %default %merge.phi = phi i32 [ %sub, %default ], [ 0, %onzero ], [ 1, %onone ], [ 2, %ontwo ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa } ; Here switch will always jump to the %ontwo label define i32 @test_switch_ne_one_case() { ; CHECK-LABEL: @test_switch_ne_one_case( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 4, [[SUM]] ; CHECK-NEXT: switch i32 [[SUB]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i32 0, label [[ONZERO:%.*]] ; CHECK-NEXT: i32 1, label [[ONONE:%.*]] ; CHECK-NEXT: i32 4, label [[ONTWO:%.*]] ; CHECK-NEXT: ] ; CHECK: default: ; CHECK-NEXT: br label [[BACKEDGE:%.*]] ; CHECK: onzero: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: onone: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: ontwo: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 2, [[DEFAULT]] ], [ 0, [[ONZERO]] ], [ 1, [[ONONE]] ], [ [[SUB]], [[ONTWO]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 4 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 4, %sum switch i32 %sub, label %default [ i32 0, label %onzero i32 1, label %onone i32 4, label %ontwo ] default: ; preds = %loop br label %backedge onzero: ; preds = %loop br label %backedge onone: ; preds = %loop br label %backedge ontwo: ; preds = %loop br label %backedge backedge: ; preds = %ontwo, %onone, %onzero, %default %merge.phi = phi i32 [ 2, %default ], [ 0, %onzero ], [ 1, %onone ], [ %sub, %ontwo ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 4 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa } ; Here switch will always jump to the %backedge label, but there are two jumps to this label in switch define i32 @test_switch_ne_one_case_identical_jumps() { ; CHECK-LABEL: @test_switch_ne_one_case_identical_jumps( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[SUM:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: [[SUB:%.*]] = sub i32 2, [[SUM]] ; CHECK-NEXT: switch i32 [[SUB]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i32 0, label [[FIRST_BLOCK:%.*]] ; CHECK-NEXT: i32 1, label [[BACKEDGE:%.*]] ; CHECK-NEXT: i32 2, label [[BACKEDGE]] ; CHECK-NEXT: ] ; CHECK: default: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: first_block: ; CHECK-NEXT: br label [[BACKEDGE]] ; CHECK: backedge: ; CHECK-NEXT: [[MERGE_PHI:%.*]] = phi i32 [ 0, [[DEFAULT]] ], [ 1, [[FIRST_BLOCK]] ], [ [[SUB]], [[LOOP]] ], [ [[SUB]], [[LOOP]] ] ; CHECK-NEXT: [[SUM_NEXT:%.*]] = add i32 [[SUM]], [[MERGE_PHI]] ; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp ne i32 [[SUM_NEXT]], 2 ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: [[SUM_NEXT_LCSSA:%.*]] = phi i32 [ [[SUM_NEXT]], [[BACKEDGE]] ] ; CHECK-NEXT: ret i32 [[SUM_NEXT_LCSSA]] ; entry: br label %loop loop: ; preds = %backedge, %entry %sum = phi i32 [ 0, %entry ], [ %sum.next, %backedge ] %sub = sub i32 2, %sum switch i32 %sub, label %default [ i32 0, label %first_block i32 1, label %backedge i32 2, label %backedge ] default: ; preds = %loop br label %backedge first_block: ; preds = %loop br label %backedge backedge: ; preds = %first_block, %default, %loop, %loop %merge.phi = phi i32 [ 0, %default ], [ 1, %first_block ], [ %sub, %loop ], [ %sub, %loop ] %sum.next = add i32 %sum, %merge.phi %loop.cond = icmp ne i32 %sum.next, 2 br i1 %loop.cond, label %loop, label %done done: ; preds = %backedge %sum.next.lcssa = phi i32 [ %sum.next, %backedge ] ret i32 %sum.next.lcssa } @g = external global i32 define void @ptr54615(i32* byval(i32) %arg) { ; CHECK-LABEL: @ptr54615( ; CHECK-NEXT: br label [[FOR_COND:%.*]] ; CHECK: for.cond: ; CHECK-NEXT: [[CAST:%.*]] = bitcast i32* @g to i32* ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32* [[CAST]], [[ARG:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[FOR_END:%.*]], label [[FOR_COND]] ; CHECK: for.end: ; CHECK-NEXT: ret void ; br label %for.cond for.cond: %cast = bitcast i32* @g to i32* %cmp = icmp eq i32* %cast, %arg br i1 %cmp, label %for.end, label %for.cond for.end: ret void }