; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128:n8:16:32:64" define i32 @test1(i32 %A, i1 %b) { ; CHECK-LABEL: @test1( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: ret i32 [[A:%.*]] ; CHECK: BB2: ; CHECK-NEXT: ret i32 [[A]] ; BB0: br i1 %b, label %BB1, label %BB2 BB1: ; Combine away one argument PHI nodes %B = phi i32 [ %A, %BB0 ] ret i32 %B BB2: ret i32 %A } define i32 @test2(i32 %A, i1 %b) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: BB2: ; CHECK-NEXT: ret i32 [[A:%.*]] ; BB0: br i1 %b, label %BB1, label %BB2 BB1: br label %BB2 BB2: ; Combine away PHI nodes with same values %B = phi i32 [ %A, %BB0 ], [ %A, %BB1 ] ret i32 %B } define i32 @test3(i32 %A, i1 %b) { ; CHECK-LABEL: @test3( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: br i1 [[B:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: ret i32 [[A:%.*]] ; BB0: br label %Loop Loop: ; PHI has same value always. %B = phi i32 [ %A, %BB0 ], [ %B, %Loop ] br i1 %b, label %Loop, label %Exit Exit: ret i32 %B } define i32 @test4(i1 %b) { ; CHECK-LABEL: @test4( ; CHECK-NEXT: BB0: ; CHECK-NEXT: ret i32 7 ; CHECK: Loop: ; CHECK-NEXT: br i1 [[B:%.*]], label [[L2:%.*]], label [[LOOP:%.*]] ; CHECK: L2: ; CHECK-NEXT: br label [[LOOP]] ; BB0: ; Loop is unreachable ret i32 7 Loop: ; preds = %L2, %Loop ; PHI has same value always. %B = phi i32 [ %B, %L2 ], [ %B, %Loop ] br i1 %b, label %L2, label %Loop L2: ; preds = %Loop br label %Loop } define i32 @test5(i32 %A, i1 %b) { ; CHECK-LABEL: @test5( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: br i1 [[B:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: ret i32 [[A:%.*]] ; BB0: br label %Loop Loop: ; preds = %Loop, %BB0 ; PHI has same value always. %B = phi i32 [ %A, %BB0 ], [ undef, %Loop ] br i1 %b, label %Loop, label %Exit Exit: ; preds = %Loop ret i32 %B } define i32 @test6(i16 %A, i1 %b) { ; CHECK-LABEL: @test6( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: BB2: ; CHECK-NEXT: [[B:%.*]] = zext i16 [[A:%.*]] to i32 ; CHECK-NEXT: ret i32 [[B]] ; BB0: %X = zext i16 %A to i32 br i1 %b, label %BB1, label %BB2 BB1: %Y = zext i16 %A to i32 br label %BB2 BB2: ;; Suck casts into phi %B = phi i32 [ %X, %BB0 ], [ %Y, %BB1 ] ret i32 %B } define i32 @test7(i32 %A, i1 %b) { ; CHECK-LABEL: @test7( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: br i1 [[B:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: ret i32 0 ; BB0: br label %Loop Loop: ; preds = %Loop, %BB0 ; PHI is dead. %B = phi i32 [ %A, %BB0 ], [ %C, %Loop ] %C = add i32 %B, 123 br i1 %b, label %Loop, label %Exit Exit: ; preds = %Loop ret i32 0 } define i32* @test8({ i32, i32 } *%A, i1 %b) { ; CHECK-LABEL: @test8( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: BB2: ; CHECK-NEXT: [[B:%.*]] = getelementptr { i32, i32 }, { i32, i32 }* [[A:%.*]], i64 0, i32 1 ; CHECK-NEXT: ret i32* [[B]] ; BB0: %X = getelementptr inbounds { i32, i32 }, { i32, i32 } *%A, i32 0, i32 1 br i1 %b, label %BB1, label %BB2 BB1: %Y = getelementptr { i32, i32 }, { i32, i32 } *%A, i32 0, i32 1 br label %BB2 BB2: ;; Suck GEPs into phi %B = phi i32* [ %X, %BB0 ], [ %Y, %BB1 ] ret i32* %B } define i32 @test9(i32* %A, i32* %B) { ; CHECK-LABEL: @test9( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[C:%.*]] = icmp eq i32* [[A:%.*]], null ; CHECK-NEXT: br i1 [[C]], label [[BB1:%.*]], label [[BB:%.*]] ; CHECK: bb: ; CHECK-NEXT: br label [[BB2:%.*]] ; CHECK: bb1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: bb2: ; CHECK-NEXT: [[E_IN:%.*]] = phi i32* [ [[B:%.*]], [[BB]] ], [ [[A]], [[BB1]] ] ; CHECK-NEXT: [[E:%.*]] = load i32, i32* [[E_IN]], align 1 ; CHECK-NEXT: ret i32 [[E]] ; entry: %c = icmp eq i32* %A, null br i1 %c, label %bb1, label %bb bb: %C = load i32, i32* %B, align 1 br label %bb2 bb1: %D = load i32, i32* %A, align 1 br label %bb2 bb2: %E = phi i32 [ %C, %bb ], [ %D, %bb1 ] ret i32 %E } define i32 @test10(i32* %A, i32* %B) { ; CHECK-LABEL: @test10( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[C:%.*]] = icmp eq i32* [[A:%.*]], null ; CHECK-NEXT: br i1 [[C]], label [[BB1:%.*]], label [[BB:%.*]] ; CHECK: bb: ; CHECK-NEXT: br label [[BB2:%.*]] ; CHECK: bb1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: bb2: ; CHECK-NEXT: [[E_IN:%.*]] = phi i32* [ [[B:%.*]], [[BB]] ], [ [[A]], [[BB1]] ] ; CHECK-NEXT: [[E:%.*]] = load i32, i32* [[E_IN]], align 16 ; CHECK-NEXT: ret i32 [[E]] ; entry: %c = icmp eq i32* %A, null br i1 %c, label %bb1, label %bb bb: %C = load i32, i32* %B, align 16 br label %bb2 bb1: %D = load i32, i32* %A, align 32 br label %bb2 bb2: %E = phi i32 [ %C, %bb ], [ %D, %bb1 ] ret i32 %E } ; PR1777 declare i1 @test11a() define i1 @test11() { ; CHECK-LABEL: @test11( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[B:%.*]] = call i1 @test11a() ; CHECK-NEXT: br i1 [[B]], label [[ONE:%.*]], label [[TWO:%.*]] ; CHECK: one: ; CHECK-NEXT: [[C:%.*]] = call i1 @test11a() ; CHECK-NEXT: br i1 [[C]], label [[TWO]], label [[END:%.*]] ; CHECK: two: ; CHECK-NEXT: [[D:%.*]] = call i1 @test11a() ; CHECK-NEXT: br i1 [[D]], label [[ONE]], label [[END]] ; CHECK: end: ; CHECK-NEXT: [[Z:%.*]] = call i1 @test11a() ; CHECK-NEXT: ret i1 [[Z]] ; entry: %a = alloca i32 %i = ptrtoint i32* %a to i64 %b = call i1 @test11a() br i1 %b, label %one, label %two one: %x = phi i64 [%i, %entry], [%y, %two] %c = call i1 @test11a() br i1 %c, label %two, label %end two: %y = phi i64 [%i, %entry], [%x, %one] %d = call i1 @test11a() br i1 %d, label %one, label %end end: %f = phi i64 [ %x, %one], [%y, %two] ; Change the %f to %i, and the optimizer suddenly becomes a lot smarter ; even though %f must equal %i at this point %g = inttoptr i64 %f to i32* store i32 10, i32* %g %z = call i1 @test11a() ret i1 %z } define i64 @test12(i1 %cond, i8* %Ptr, i64 %Val) { ; CHECK-LABEL: @test12( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[END:%.*]], label [[TWO:%.*]] ; CHECK: two: ; CHECK-NEXT: br label [[END]] ; CHECK: end: ; CHECK-NEXT: [[T869_0_OFF64:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[VAL:%.*]], [[TWO]] ] ; CHECK-NEXT: [[T41:%.*]] = ptrtoint i8* [[PTR:%.*]] to i64 ; CHECK-NEXT: [[T2:%.*]] = add i64 [[T869_0_OFF64]], [[T41]] ; CHECK-NEXT: ret i64 [[T2]] ; entry: %t41 = ptrtoint i8* %Ptr to i64 %t42 = zext i64 %t41 to i128 br i1 %cond, label %end, label %two two: %t36 = zext i64 %Val to i128 ; <i128> [#uses=1] %t37 = shl i128 %t36, 64 ; <i128> [#uses=1] %ins39 = or i128 %t42, %t37 ; <i128> [#uses=1] br label %end end: %t869.0 = phi i128 [ %t42, %entry ], [ %ins39, %two ] %t32 = trunc i128 %t869.0 to i64 ; <i64> [#uses=1] %t29 = lshr i128 %t869.0, 64 ; <i128> [#uses=1] %t30 = trunc i128 %t29 to i64 ; <i64> [#uses=1] %t2 = add i64 %t32, %t30 ret i64 %t2 } declare void @test13f(double, i32) define void @test13(i1 %cond, i32 %V1, double %Vald) { ; CHECK-LABEL: @test13( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[END:%.*]], label [[TWO:%.*]] ; CHECK: two: ; CHECK-NEXT: br label [[END]] ; CHECK: end: ; CHECK-NEXT: [[TMP0:%.*]] = phi double [ 0.000000e+00, [[ENTRY:%.*]] ], [ [[VALD:%.*]], [[TWO]] ] ; CHECK-NEXT: call void @test13f(double [[TMP0]], i32 [[V1:%.*]]) ; CHECK-NEXT: ret void ; entry: %t42 = zext i32 %V1 to i128 br i1 %cond, label %end, label %two two: %Val = bitcast double %Vald to i64 %t36 = zext i64 %Val to i128 ; <i128> [#uses=1] %t37 = shl i128 %t36, 64 ; <i128> [#uses=1] %ins39 = or i128 %t42, %t37 ; <i128> [#uses=1] br label %end end: %t869.0 = phi i128 [ %t42, %entry ], [ %ins39, %two ] %t32 = trunc i128 %t869.0 to i32 %t29 = lshr i128 %t869.0, 64 ; <i128> [#uses=1] %t30 = trunc i128 %t29 to i64 ; <i64> [#uses=1] %t31 = bitcast i64 %t30 to double call void @test13f(double %t31, i32 %t32) ret void } define i640 @test14a(i320 %A, i320 %B, i1 %b1) { ; CHECK-LABEL: @test14a( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: [[C_IN:%.*]] = phi i320 [ [[A:%.*]], [[BB0:%.*]] ], [ [[B:%.*]], [[LOOP]] ] ; CHECK-NEXT: br i1 [[B1:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: [[C:%.*]] = zext i320 [[C_IN]] to i640 ; CHECK-NEXT: ret i640 [[C]] ; BB0: %a = zext i320 %A to i640 %b = zext i320 %B to i640 br label %Loop Loop: %C = phi i640 [ %a, %BB0 ], [ %b, %Loop ] br i1 %b1, label %Loop, label %Exit Exit: ; preds = %Loop ret i640 %C } define i160 @test14b(i320 %pA, i320 %pB, i1 %b1) { ; CHECK-LABEL: @test14b( ; CHECK-NEXT: BB0: ; CHECK-NEXT: [[A:%.*]] = trunc i320 [[PA:%.*]] to i160 ; CHECK-NEXT: [[B:%.*]] = trunc i320 [[PB:%.*]] to i160 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: [[C:%.*]] = phi i160 [ [[A]], [[BB0:%.*]] ], [ [[B]], [[LOOP]] ] ; CHECK-NEXT: br i1 [[B1:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: ret i160 [[C]] ; BB0: %a = trunc i320 %pA to i160 %b = trunc i320 %pB to i160 br label %Loop Loop: %C = phi i160 [ %a, %BB0 ], [ %b, %Loop ] br i1 %b1, label %Loop, label %Exit Exit: ; preds = %Loop ret i160 %C } declare i64 @test15a(i64) define i64 @test15b(i64 %A, i1 %b) { ; CHECK-LABEL: @test15b( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[B:%.*]], label [[ONE:%.*]], label [[TWO:%.*]] ; CHECK: one: ; CHECK-NEXT: [[X_OFF64:%.*]] = phi i64 [ [[A:%.*]], [[ENTRY:%.*]] ], [ [[Y_OFF64:%.*]], [[TWO]] ] ; CHECK-NEXT: [[C:%.*]] = call i64 @test15a(i64 [[X_OFF64]]) ; CHECK-NEXT: br label [[TWO]] ; CHECK: two: ; CHECK-NEXT: [[Y_OFF0:%.*]] = phi i64 [ [[A]], [[ENTRY]] ], [ [[C]], [[ONE]] ] ; CHECK-NEXT: [[Y_OFF64]] = phi i64 [ [[A]], [[ENTRY]] ], [ 0, [[ONE]] ] ; CHECK-NEXT: [[D:%.*]] = call i64 @test15a(i64 [[Y_OFF64]]) ; CHECK-NEXT: [[TMP0:%.*]] = and i64 [[D]], 1 ; CHECK-NEXT: [[D1_NOT:%.*]] = icmp eq i64 [[TMP0]], 0 ; CHECK-NEXT: br i1 [[D1_NOT]], label [[END:%.*]], label [[ONE]] ; CHECK: end: ; CHECK-NEXT: ret i64 [[Y_OFF0]] ; entry: %i0 = zext i64 %A to i128 %i1 = shl i128 %i0, 64 %i = or i128 %i1, %i0 br i1 %b, label %one, label %two one: %x = phi i128 [%i, %entry], [%y, %two] %x1 = lshr i128 %x, 64 %x2 = trunc i128 %x1 to i64 %c = call i64 @test15a(i64 %x2) %c1 = zext i64 %c to i128 br label %two two: %y = phi i128 [%i, %entry], [%c1, %one] %y1 = lshr i128 %y, 64 %y2 = trunc i128 %y1 to i64 %d = call i64 @test15a(i64 %y2) %d1 = trunc i64 %d to i1 br i1 %d1, label %one, label %end end: %g = trunc i128 %y to i64 ret i64 %g } ; PR6512 - Shouldn't merge loads from different addr spaces. define i32 @test16(i32 addrspace(1)* %pointer1, i32 %flag, i32* %pointer2) ; CHECK-LABEL: @test16( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[RETVAL:%.*]] = alloca i32, align 4 ; CHECK-NEXT: [[POINTER1_ADDR:%.*]] = alloca i32 addrspace(1)*, align 8 ; CHECK-NEXT: [[POINTER2_ADDR:%.*]] = alloca i32*, align 8 ; CHECK-NEXT: store i32 addrspace(1)* [[POINTER1:%.*]], i32 addrspace(1)** [[POINTER1_ADDR]], align 8 ; CHECK-NEXT: store i32* [[POINTER2:%.*]], i32** [[POINTER2_ADDR]], align 8 ; CHECK-NEXT: [[TOBOOL_NOT:%.*]] = icmp eq i32 [[FLAG:%.*]], 0 ; CHECK-NEXT: br i1 [[TOBOOL_NOT]], label [[IF_ELSE:%.*]], label [[IF_THEN:%.*]] ; CHECK: return: ; CHECK-NEXT: [[T7:%.*]] = load i32, i32* [[RETVAL]], align 4 ; CHECK-NEXT: ret i32 [[T7]] ; CHECK: if.end: ; CHECK-NEXT: [[STOREMERGE:%.*]] = phi i32 [ [[T5:%.*]], [[IF_ELSE]] ], [ [[T2:%.*]], [[IF_THEN]] ] ; CHECK-NEXT: store i32 [[STOREMERGE]], i32* [[RETVAL]], align 4 ; CHECK-NEXT: br label [[RETURN:%.*]] ; CHECK: if.then: ; CHECK-NEXT: [[T1:%.*]] = load i32 addrspace(1)*, i32 addrspace(1)** [[POINTER1_ADDR]], align 8 ; CHECK-NEXT: [[T2]] = load i32, i32 addrspace(1)* [[T1]], align 4 ; CHECK-NEXT: br label [[IF_END:%.*]] ; CHECK: if.else: ; CHECK-NEXT: [[T3:%.*]] = load i32*, i32** [[POINTER2_ADDR]], align 8 ; CHECK-NEXT: [[T5]] = load i32, i32* [[T3]], align 4 ; CHECK-NEXT: br label [[IF_END]] ; nounwind { entry: %retval = alloca i32, align 4 ; <i32*> [#uses=2] %pointer1.addr = alloca i32 addrspace(1)*, align 4 ; <i32 addrspace(1)**> %flag.addr = alloca i32, align 4 ; <i32*> [#uses=2] %pointer2.addr = alloca i32*, align 4 ; <i32**> [#uses=2] %res = alloca i32, align 4 ; <i32*> [#uses=4] store i32 addrspace(1)* %pointer1, i32 addrspace(1)** %pointer1.addr store i32 %flag, i32* %flag.addr store i32* %pointer2, i32** %pointer2.addr store i32 10, i32* %res %t = load i32, i32* %flag.addr ; <i32> [#uses=1] %tobool = icmp ne i32 %t, 0 ; <i1> [#uses=1] br i1 %tobool, label %if.then, label %if.else return: ; preds = %if.end %t7 = load i32, i32* %retval ; <i32> [#uses=1] ret i32 %t7 if.end: ; preds = %if.else, %if.then %t6 = load i32, i32* %res ; <i32> [#uses=1] store i32 %t6, i32* %retval br label %return if.then: ; preds = %entry %t1 = load i32 addrspace(1)*, i32 addrspace(1)** %pointer1.addr ; <i32 addrspace(1)*> %arrayidx = getelementptr i32, i32 addrspace(1)* %t1, i32 0 ; <i32 addrspace(1)*> [#uses=1] %t2 = load i32, i32 addrspace(1)* %arrayidx ; <i32> [#uses=1] store i32 %t2, i32* %res br label %if.end if.else: ; preds = %entry %t3 = load i32*, i32** %pointer2.addr ; <i32*> [#uses=1] %arrayidx4 = getelementptr i32, i32* %t3, i32 0 ; <i32*> [#uses=1] %t5 = load i32, i32* %arrayidx4 ; <i32> [#uses=1] store i32 %t5, i32* %res br label %if.end } ; PR4413 declare i32 @ext() define i32 @test17(i1 %a) { ; CHECK-LABEL: @test17( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[A:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: bb1: ; CHECK-NEXT: [[TMP0:%.*]] = tail call i32 @ext() ; CHECK-NEXT: br label [[BB2]] ; CHECK: bb2: ; CHECK-NEXT: [[RES:%.*]] = phi i32 [ [[TMP0]], [[BB1]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[RES]] ; entry: br i1 %a, label %bb1, label %bb2 bb1: ; preds = %entry %0 = tail call i32 @ext() ; <i32> [#uses=1] br label %bb2 bb2: ; preds = %bb1, %entry %cond = phi i1 [ true, %bb1 ], [ false, %entry ] ; <i1> [#uses=1] %val = phi i32 [ %0, %bb1 ], [ 0, %entry ] ; <i32> [#uses=1] %res = select i1 %cond, i32 %val, i32 0 ; <i32> [#uses=1] ret i32 %res } ; Atomic and non-atomic loads should not be combined. define i32 @PR51435(i32* %ptr, i32* %atomic_ptr, i1 %c) { ; CHECK-LABEL: @PR51435( ; CHECK: entry: ; CHECK-NEXT: [[NON_ATOMIC:%.*]] = load i32, i32* %ptr, align 4 ; CHECK: if: ; CHECK-NEXT: [[ATOMIC:%.*]] = load atomic i32, i32* %atomic_ptr acquire, align 4 ; CHECK: end: ; CHECK-NEXT: [[COND:%.*]] = phi i32 [ [[NON_ATOMIC]], %entry ], [ [[ATOMIC]], %if ] ; CHECK-NEXT: ret i32 [[COND]] entry: %x = load i32, i32* %ptr, align 4 br i1 %c, label %if, label %end if: %y = load atomic i32, i32* %atomic_ptr acquire, align 4 br label %end end: %cond = phi i32 [ %x, %entry ], [ %y, %if ] ret i32 %cond } define i1 @test18(i1 %cond) { ; CHECK-LABEL: @test18( ; CHECK-NEXT: br i1 [[COND:%.*]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: br label [[RET:%.*]] ; CHECK: false: ; CHECK-NEXT: br label [[RET]] ; CHECK: ret: ; CHECK-NEXT: ret i1 false ; %zero = alloca i32 %one = alloca i32 br i1 %cond, label %true, label %false true: br label %ret false: br label %ret ret: %ptr = phi i32* [ %zero, %true ] , [ %one, %false ] %isnull = icmp eq i32* %ptr, null ret i1 %isnull } define i1 @test19(i1 %cond, double %x) { ; CHECK-LABEL: @test19( ; CHECK-NEXT: br i1 [[COND:%.*]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: br label [[RET:%.*]] ; CHECK: false: ; CHECK-NEXT: br label [[RET]] ; CHECK: ret: ; CHECK-NEXT: ret i1 true ; br i1 %cond, label %true, label %false true: br label %ret false: br label %ret ret: %p = phi double [ %x, %true ], [ 0x7FF0000000000000, %false ]; RHS = +infty %cmp = fcmp ule double %x, %p ret i1 %cmp } define i1 @test20(i1 %cond) { ; CHECK-LABEL: @test20( ; CHECK-NEXT: br i1 [[COND:%.*]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: br label [[RET:%.*]] ; CHECK: false: ; CHECK-NEXT: br label [[RET]] ; CHECK: ret: ; CHECK-NEXT: ret i1 false ; %a = alloca i32 %b = alloca i32 %c = alloca i32 br i1 %cond, label %true, label %false true: br label %ret false: br label %ret ret: %p = phi i32* [ %a, %true ], [ %b, %false ] %r = icmp eq i32* %p, %c ret i1 %r } define i1 @test21(i1 %c1, i1 %c2) { ; CHECK-LABEL: @test21( ; CHECK-NEXT: br i1 [[C1:%.*]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: false: ; CHECK-NEXT: br label [[LOOP]] ; CHECK: loop: ; CHECK-NEXT: br i1 [[C2:%.*]], label [[RET:%.*]], label [[LOOP]] ; CHECK: ret: ; CHECK-NEXT: ret i1 false ; %a = alloca i32 %b = alloca i32 %c = alloca i32 br i1 %c1, label %true, label %false true: br label %loop false: br label %loop loop: %p = phi i32* [ %a, %true ], [ %b, %false ], [ %p, %loop ] %r = icmp eq i32* %p, %c br i1 %c2, label %ret, label %loop ret: ret i1 %r } define void @test22() { ; CHECK-LABEL: @test22( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: loop: ; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[Y:%.*]], [[LOOP]] ] ; CHECK-NEXT: [[Y]] = add i32 [[PHI]], 1 ; CHECK-NEXT: [[O:%.*]] = or i32 [[Y]], [[PHI]] ; CHECK-NEXT: [[E:%.*]] = icmp eq i32 [[O]], [[Y]] ; CHECK-NEXT: br i1 [[E]], label [[LOOP]], label [[RET:%.*]] ; CHECK: ret: ; CHECK-NEXT: ret void ; entry: br label %loop loop: %phi = phi i32 [ 0, %entry ], [ %y, %loop ] %y = add i32 %phi, 1 %o = or i32 %y, %phi %e = icmp eq i32 %o, %y br i1 %e, label %loop, label %ret ret: ret void } define i32 @test23(i32 %A, i1 %pb, i32 * %P) { ; CHECK-LABEL: @test23( ; CHECK-NEXT: BB0: ; CHECK-NEXT: [[PHI_BO:%.*]] = add i32 [[A:%.*]], 19 ; CHECK-NEXT: br label [[LOOP:%.*]] ; CHECK: Loop: ; CHECK-NEXT: [[B:%.*]] = phi i32 [ [[PHI_BO]], [[BB0:%.*]] ], [ 61, [[LOOP]] ] ; CHECK-NEXT: store i32 [[B]], i32* [[P:%.*]], align 4 ; CHECK-NEXT: br i1 [[PB:%.*]], label [[LOOP]], label [[EXIT:%.*]] ; CHECK: Exit: ; CHECK-NEXT: ret i32 [[B]] ; BB0: br label %Loop Loop: ; preds = %Loop, %BB0 ; PHI has same value always. %B = phi i32 [ %A, %BB0 ], [ 42, %Loop ] %D = add i32 %B, 19 store i32 %D, i32* %P br i1 %pb, label %Loop, label %Exit Exit: ; preds = %Loop %E = add i32 %B, 19 ret i32 %E } define i32 @test24(i32 %A, i1 %cond) { ; CHECK-LABEL: @test24( ; CHECK-NEXT: BB0: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: br label [[BB2]] ; CHECK: BB2: ; CHECK-NEXT: [[C:%.*]] = add nuw i32 [[A:%.*]], 1 ; CHECK-NEXT: ret i32 [[C]] ; BB0: %X = add nuw nsw i32 %A, 1 br i1 %cond, label %BB1, label %BB2 BB1: %Y = add nuw i32 %A, 1 br label %BB2 BB2: %C = phi i32 [ %X, %BB0 ], [ %Y, %BB1 ] ret i32 %C } ; Same as test11, but used to be missed due to a bug. declare i1 @test25a() define i1 @test25() { ; CHECK-LABEL: @test25( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[B:%.*]] = call i1 @test25a() ; CHECK-NEXT: br i1 [[B]], label [[ONE:%.*]], label [[TWO:%.*]] ; CHECK: one: ; CHECK-NEXT: [[C:%.*]] = call i1 @test25a() ; CHECK-NEXT: br i1 [[C]], label [[TWO]], label [[END:%.*]] ; CHECK: two: ; CHECK-NEXT: [[D:%.*]] = call i1 @test25a() ; CHECK-NEXT: br i1 [[D]], label [[ONE]], label [[END]] ; CHECK: end: ; CHECK-NEXT: [[Z:%.*]] = call i1 @test25a() ; CHECK-NEXT: ret i1 [[Z]] ; entry: %a = alloca i32 %i = ptrtoint i32* %a to i64 %b = call i1 @test25a() br i1 %b, label %one, label %two one: %x = phi i64 [%y, %two], [%i, %entry] %c = call i1 @test25a() br i1 %c, label %two, label %end two: %y = phi i64 [%x, %one], [%i, %entry] %d = call i1 @test25a() br i1 %d, label %one, label %end end: %f = phi i64 [ %x, %one], [%y, %two] ; Change the %f to %i, and the optimizer suddenly becomes a lot smarter ; even though %f must equal %i at this point %g = inttoptr i64 %f to i32* store i32 10, i32* %g %z = call i1 @test25a() ret i1 %z } declare i1 @test26a() define i1 @test26(i32 %n) { ; CHECK-LABEL: @test26( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[B:%.*]] = call i1 @test26a() ; CHECK-NEXT: br label [[ONE:%.*]] ; CHECK: one: ; CHECK-NEXT: [[C:%.*]] = call i1 @test26a() ; CHECK-NEXT: switch i32 [[N:%.*]], label [[END:%.*]] [ ; CHECK-NEXT: i32 2, label [[TWO:%.*]] ; CHECK-NEXT: i32 3, label [[THREE:%.*]] ; CHECK-NEXT: ] ; CHECK: two: ; CHECK-NEXT: [[D:%.*]] = call i1 @test26a() ; CHECK-NEXT: switch i32 [[N]], label [[END]] [ ; CHECK-NEXT: i32 10, label [[ONE]] ; CHECK-NEXT: i32 30, label [[THREE]] ; CHECK-NEXT: ] ; CHECK: three: ; CHECK-NEXT: [[E:%.*]] = call i1 @test26a() ; CHECK-NEXT: br i1 [[E]], label [[ONE]], label [[TWO]] ; CHECK: end: ; CHECK-NEXT: [[Z:%.*]] = call i1 @test26a() ; CHECK-NEXT: ret i1 [[Z]] ; entry: %a = alloca i32 %i = ptrtoint i32* %a to i64 %b = call i1 @test26a() br label %one one: %x = phi i64 [%y, %two], [%w, %three], [%i, %entry] %c = call i1 @test26a() switch i32 %n, label %end [ i32 2, label %two i32 3, label %three ] two: %y = phi i64 [%x, %one], [%w, %three] %d = call i1 @test26a() switch i32 %n, label %end [ i32 10, label %one i32 30, label %three ] three: %w = phi i64 [%y, %two], [%x, %one] %e = call i1 @test26a() br i1 %e, label %one, label %two end: %f = phi i64 [ %x, %one], [%y, %two] ; Change the %f to %i, and the optimizer suddenly becomes a lot smarter ; even though %f must equal %i at this point %g = inttoptr i64 %f to i32* store i32 10, i32* %g %z = call i1 @test26a() ret i1 %z } define i32 @test27(i1 %b) { ; CHECK-LABEL: @test27( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[DONE:%.*]] ; CHECK: done: ; CHECK-NEXT: ret i32 undef ; entry: br label %done done: %y = phi i32 [ undef, %entry ] ret i32 %y } ; We should be able to fold the zexts to the other side of the phi ; even though there's a constant value input to the phi. This is ; because we can shrink that constant to the smaller phi type. define i1 @PR24766(i8 %x1, i8 %x2, i8 %condition) { ; CHECK-LABEL: @PR24766( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CONV:%.*]] = sext i8 [[CONDITION:%.*]] to i32 ; CHECK-NEXT: switch i32 [[CONV]], label [[EPILOG:%.*]] [ ; CHECK-NEXT: i32 0, label [[SW1:%.*]] ; CHECK-NEXT: i32 1, label [[SW2:%.*]] ; CHECK-NEXT: ] ; CHECK: sw1: ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i8 [[X1:%.*]], [[X2:%.*]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: sw2: ; CHECK-NEXT: [[CMP2:%.*]] = icmp sle i8 [[X1]], [[X2]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: epilog: ; CHECK-NEXT: [[CONDITIONMET_SHRUNK:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[CMP2]], [[SW2]] ], [ [[CMP1]], [[SW1]] ] ; CHECK-NEXT: ret i1 [[CONDITIONMET_SHRUNK]] ; entry: %conv = sext i8 %condition to i32 switch i32 %conv, label %epilog [ i32 0, label %sw1 i32 1, label %sw2 ] sw1: %cmp1 = icmp eq i8 %x1, %x2 %frombool1 = zext i1 %cmp1 to i8 br label %epilog sw2: %cmp2 = icmp sle i8 %x1, %x2 %frombool2 = zext i1 %cmp2 to i8 br label %epilog epilog: %conditionMet = phi i8 [ 0, %entry ], [ %frombool2, %sw2 ], [ %frombool1, %sw1 ] %tobool = icmp ne i8 %conditionMet, 0 ret i1 %tobool } ; Same as above (a phi with more than 2 operands), but no constants define i1 @PR24766_no_constants(i8 %x1, i8 %x2, i8 %condition, i1 %another_condition) { ; CHECK-LABEL: @PR24766_no_constants( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CONV:%.*]] = sext i8 [[CONDITION:%.*]] to i32 ; CHECK-NEXT: switch i32 [[CONV]], label [[EPILOG:%.*]] [ ; CHECK-NEXT: i32 0, label [[SW1:%.*]] ; CHECK-NEXT: i32 1, label [[SW2:%.*]] ; CHECK-NEXT: ] ; CHECK: sw1: ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i8 [[X1:%.*]], [[X2:%.*]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: sw2: ; CHECK-NEXT: [[CMP2:%.*]] = icmp sle i8 [[X1]], [[X2]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: epilog: ; CHECK-NEXT: [[CONDITIONMET_IN:%.*]] = phi i1 [ [[ANOTHER_CONDITION:%.*]], [[ENTRY:%.*]] ], [ [[CMP2]], [[SW2]] ], [ [[CMP1]], [[SW1]] ] ; CHECK-NEXT: ret i1 [[CONDITIONMET_IN]] ; entry: %frombool0 = zext i1 %another_condition to i8 %conv = sext i8 %condition to i32 switch i32 %conv, label %epilog [ i32 0, label %sw1 i32 1, label %sw2 ] sw1: %cmp1 = icmp eq i8 %x1, %x2 %frombool1 = zext i1 %cmp1 to i8 br label %epilog sw2: %cmp2 = icmp sle i8 %x1, %x2 %frombool2 = zext i1 %cmp2 to i8 br label %epilog epilog: %conditionMet = phi i8 [ %frombool0, %entry ], [ %frombool2, %sw2 ], [ %frombool1, %sw1 ] %tobool = icmp ne i8 %conditionMet, 0 ret i1 %tobool } ; Same as above (a phi with more than 2 operands), but two constants define i1 @PR24766_two_constants(i8 %x1, i8 %x2, i8 %condition) { ; CHECK-LABEL: @PR24766_two_constants( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CONV:%.*]] = sext i8 [[CONDITION:%.*]] to i32 ; CHECK-NEXT: switch i32 [[CONV]], label [[EPILOG:%.*]] [ ; CHECK-NEXT: i32 0, label [[SW1:%.*]] ; CHECK-NEXT: i32 1, label [[SW2:%.*]] ; CHECK-NEXT: ] ; CHECK: sw1: ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i8 [[X1:%.*]], [[X2:%.*]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: sw2: ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: epilog: ; CHECK-NEXT: [[CONDITIONMET:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ true, [[SW2]] ], [ [[CMP1]], [[SW1]] ] ; CHECK-NEXT: ret i1 [[CONDITIONMET]] ; entry: %conv = sext i8 %condition to i32 switch i32 %conv, label %epilog [ i32 0, label %sw1 i32 1, label %sw2 ] sw1: %cmp1 = icmp eq i8 %x1, %x2 %frombool1 = zext i1 %cmp1 to i8 br label %epilog sw2: %cmp2 = icmp sle i8 %x1, %x2 %frombool2 = zext i1 %cmp2 to i8 br label %epilog epilog: %conditionMet = phi i8 [ 0, %entry ], [ 1, %sw2 ], [ %frombool1, %sw1 ] %tobool = icmp ne i8 %conditionMet, 0 ret i1 %tobool } ; Same as above (a phi with more than 2 operands), but two constants and two variables define i1 @PR24766_two_constants_two_var(i8 %x1, i8 %x2, i8 %condition) { ; CHECK-LABEL: @PR24766_two_constants_two_var( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CONV:%.*]] = sext i8 [[CONDITION:%.*]] to i32 ; CHECK-NEXT: switch i32 [[CONV]], label [[EPILOG:%.*]] [ ; CHECK-NEXT: i32 0, label [[SW1:%.*]] ; CHECK-NEXT: i32 1, label [[SW2:%.*]] ; CHECK-NEXT: i32 2, label [[SW3:%.*]] ; CHECK-NEXT: ] ; CHECK: sw1: ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i8 [[X1:%.*]], [[X2:%.*]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: sw2: ; CHECK-NEXT: [[CMP2:%.*]] = icmp sle i8 [[X1]], [[X2]] ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: sw3: ; CHECK-NEXT: br label [[EPILOG]] ; CHECK: epilog: ; CHECK-NEXT: [[CONDITIONMET_SHRUNK:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[CMP2]], [[SW2]] ], [ [[CMP1]], [[SW1]] ], [ true, [[SW3]] ] ; CHECK-NEXT: ret i1 [[CONDITIONMET_SHRUNK]] ; entry: %conv = sext i8 %condition to i32 switch i32 %conv, label %epilog [ i32 0, label %sw1 i32 1, label %sw2 i32 2, label %sw3 ] sw1: %cmp1 = icmp eq i8 %x1, %x2 %frombool1 = zext i1 %cmp1 to i8 br label %epilog sw2: %cmp2 = icmp sle i8 %x1, %x2 %frombool2 = zext i1 %cmp2 to i8 br label %epilog sw3: %cmp3 = icmp sge i8 %x1, %x2 %frombool3 = zext i1 %cmp3 to i8 br label %epilog epilog: %conditionMet = phi i8 [ 0, %entry ], [ %frombool2, %sw2 ], [ %frombool1, %sw1 ], [ 1, %sw3 ] %tobool = icmp ne i8 %conditionMet, 0 ret i1 %tobool } define i1 @phi_allnonzeroconstant(i1 %c, i32 %a, i32 %b) { ; CHECK-LABEL: @phi_allnonzeroconstant( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br label [[IF_END:%.*]] ; CHECK: if.else: ; CHECK-NEXT: call void @dummy() ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: ret i1 false ; entry: br i1 %c, label %if.then, label %if.else if.then: ; preds = %entry br label %if.end if.else: ; preds = %entry call void @dummy() br label %if.end if.end: ; preds = %if.else, %if.then %x.0 = phi i32 [ 1, %if.then ], [ 2, %if.else ] %or = or i32 %x.0, %a %cmp1 = icmp eq i32 %or, 0 ret i1 %cmp1 } define i1 @phi_allnonzerononconstant(i1 %c, i32 %a, i32* nonnull %b1, i32* nonnull %b2) { ; CHECK-LABEL: @phi_allnonzerononconstant( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br label [[IF_END:%.*]] ; CHECK: if.else: ; CHECK-NEXT: call void @dummy() ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: ret i1 false ; entry: br i1 %c, label %if.then, label %if.else if.then: ; preds = %entry br label %if.end if.else: ; preds = %entry call void @dummy() br label %if.end if.end: ; preds = %if.else, %if.then %x.0 = phi i32* [ %b1, %if.then ], [ %b2, %if.else ] %cmp1 = icmp eq i32* %x.0, null ret i1 %cmp1 } declare void @dummy() define i1 @phi_knownnonzero_eq(i32 %n, i32 %s, i32* nocapture readonly %P) { ; CHECK-LABEL: @phi_knownnonzero_eq( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TOBOOL:%.*]] = icmp slt i32 [[N:%.*]], [[S:%.*]] ; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[A_0:%.*]] = phi i32 [ 1, [[IF_THEN]] ], [ [[N]], [[ENTRY:%.*]] ] ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[A_0]], 0 ; CHECK-NEXT: ret i1 [[CMP1]] ; entry: %tobool = icmp slt i32 %n, %s br i1 %tobool, label %if.end, label %if.then if.then: ; preds = %entry %0 = load i32, i32* %P %cmp = icmp eq i32 %n, %0 %1 = select i1 %cmp, i32 1, i32 2 br label %if.end if.end: ; preds = %entry, %if.then %a.0 = phi i32 [ %1, %if.then ], [ %n, %entry ] %cmp1 = icmp eq i32 %a.0, 0 ret i1 %cmp1 } define i1 @phi_knownnonzero_ne(i32 %n, i32 %s, i32* nocapture readonly %P) { ; CHECK-LABEL: @phi_knownnonzero_ne( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TOBOOL:%.*]] = icmp slt i32 [[N:%.*]], [[S:%.*]] ; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[A_0:%.*]] = phi i32 [ 1, [[IF_THEN]] ], [ [[N]], [[ENTRY:%.*]] ] ; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i32 [[A_0]], 0 ; CHECK-NEXT: ret i1 [[CMP1]] ; entry: %tobool = icmp slt i32 %n, %s br i1 %tobool, label %if.end, label %if.then if.then: ; preds = %entry %0 = load i32, i32* %P %cmp = icmp eq i32 %n, %0 %1 = select i1 %cmp, i32 1, i32 2 br label %if.end if.end: ; preds = %entry, %if.then %a.0 = phi i32 [ %1, %if.then ], [ %n, %entry ] %cmp1 = icmp ne i32 %a.0, 0 ret i1 %cmp1 } define i1 @phi_knownnonzero_eq_2(i32 %n, i32 %s, i32* nocapture readonly %P) { ; CHECK-LABEL: @phi_knownnonzero_eq_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TOBOOL:%.*]] = icmp slt i32 [[N:%.*]], [[S:%.*]] ; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br i1 true, label [[IF_ELSE:%.*]], label [[IF_END]] ; CHECK: if.else: ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[A_0:%.*]] = phi i32 [ 2, [[IF_ELSE]] ], [ [[N]], [[ENTRY:%.*]] ], [ 2, [[IF_THEN]] ] ; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 [[A_0]], 0 ; CHECK-NEXT: ret i1 [[CMP1]] ; entry: %tobool = icmp slt i32 %n, %s br i1 %tobool, label %if.then, label %if.end if.then: %tobool2 = icmp slt i32 %n, %s br i1 %tobool2, label %if.else, label %if.end if.else: ; preds = %entry %0 = load i32, i32* %P %cmp = icmp eq i32 %n, %0 %1 = select i1 %cmp, i32 1, i32 2 br label %if.end if.end: ; preds = %entry, %if.then %a.0 = phi i32 [ %1, %if.else], [ %n, %entry ], [2, %if.then] %cmp1 = icmp eq i32 %a.0, 0 ret i1 %cmp1 } define i1 @phi_knownnonzero_ne_2(i32 %n, i32 %s, i32* nocapture readonly %P) { ; CHECK-LABEL: @phi_knownnonzero_ne_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[TOBOOL:%.*]] = icmp slt i32 [[N:%.*]], [[S:%.*]] ; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_THEN:%.*]], label [[IF_END:%.*]] ; CHECK: if.then: ; CHECK-NEXT: br i1 true, label [[IF_ELSE:%.*]], label [[IF_END]] ; CHECK: if.else: ; CHECK-NEXT: br label [[IF_END]] ; CHECK: if.end: ; CHECK-NEXT: [[A_0:%.*]] = phi i32 [ 2, [[IF_ELSE]] ], [ [[N]], [[ENTRY:%.*]] ], [ 2, [[IF_THEN]] ] ; CHECK-NEXT: [[CMP1:%.*]] = icmp ne i32 [[A_0]], 0 ; CHECK-NEXT: ret i1 [[CMP1]] ; entry: %tobool = icmp slt i32 %n, %s br i1 %tobool, label %if.then, label %if.end if.then: %tobool2 = icmp slt i32 %n, %s br i1 %tobool2, label %if.else, label %if.end if.else: ; preds = %entry %0 = load i32, i32* %P %cmp = icmp eq i32 %n, %0 %1 = select i1 %cmp, i32 1, i32 2 br label %if.end if.end: ; preds = %entry, %if.then %a.0 = phi i32 [ %1, %if.else], [ %n, %entry ], [2, %if.then] %cmp1 = icmp ne i32 %a.0, 0 ret i1 %cmp1 } ; This would crash trying to delete an instruction (conv) ; that still had uses because the user (the phi) was not ; updated to remove a use from an unreachable block (g.exit). define void @main(i1 %cond, i16 %x) { ; CHECK-LABEL: @main( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_COND:%.*]] ; CHECK: for.cond: ; CHECK-NEXT: br i1 [[COND:%.*]], label [[FOR_END:%.*]], label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: unreachable ; CHECK: g.exit: ; CHECK-NEXT: br label [[FOR_COND]] ; CHECK: for.end: ; CHECK-NEXT: ret void ; entry: br label %for.cond for.cond: %p = phi double [ %conv, %g.exit ], [ undef, %entry ] br i1 %cond, label %for.end, label %for.body for.body: %conv = sitofp i16 %x to double unreachable g.exit: br label %for.cond for.end: store double %p, double* undef ret void }