; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s declare i8 @llvm.abs.i8(i8, i1) declare i32 @llvm.abs.i32(i32, i1) declare <4 x i32> @llvm.abs.v4i32(<4 x i32>, i1) declare <3 x i82> @llvm.abs.v3i82(<3 x i82>, i1) declare void @llvm.assume(i1) ; abs preserves trailing zeros so the second and is unneeded define i32 @abs_trailing_zeros(i32 %x) { ; CHECK-LABEL: @abs_trailing_zeros( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], -4 ; CHECK-NEXT: [[ABS:%.*]] = call i32 @llvm.abs.i32(i32 [[AND]], i1 false) ; CHECK-NEXT: ret i32 [[ABS]] ; %and = and i32 %x, -4 %abs = call i32 @llvm.abs.i32(i32 %and, i1 false) %and2 = and i32 %abs, -2 ret i32 %and2 } define <4 x i32> @abs_trailing_zeros_vec(<4 x i32> %x) { ; CHECK-LABEL: @abs_trailing_zeros_vec( ; CHECK-NEXT: [[AND:%.*]] = and <4 x i32> [[X:%.*]], <i32 -4, i32 -8, i32 -16, i32 -32> ; CHECK-NEXT: [[ABS:%.*]] = call <4 x i32> @llvm.abs.v4i32(<4 x i32> [[AND]], i1 false) ; CHECK-NEXT: ret <4 x i32> [[ABS]] ; %and = and <4 x i32> %x, <i32 -4, i32 -8, i32 -16, i32 -32> %abs = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %and, i1 false) %and2 = and <4 x i32> %abs, <i32 -2, i32 -2, i32 -2, i32 -2> ret <4 x i32> %and2 } ; negative test, can't remove the second and based on trailing zeroes. ; FIXME: Could remove the first and using demanded bits. define i32 @abs_trailing_zeros_negative(i32 %x) { ; CHECK-LABEL: @abs_trailing_zeros_negative( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], -2 ; CHECK-NEXT: [[ABS:%.*]] = call i32 @llvm.abs.i32(i32 [[AND]], i1 false) ; CHECK-NEXT: [[AND2:%.*]] = and i32 [[ABS]], -4 ; CHECK-NEXT: ret i32 [[AND2]] ; %and = and i32 %x, -2 %abs = call i32 @llvm.abs.i32(i32 %and, i1 false) %and2 = and i32 %abs, -4 ret i32 %and2 } define <4 x i32> @abs_trailing_zeros_negative_vec(<4 x i32> %x) { ; CHECK-LABEL: @abs_trailing_zeros_negative_vec( ; CHECK-NEXT: [[AND:%.*]] = and <4 x i32> [[X:%.*]], <i32 -2, i32 -2, i32 -2, i32 -2> ; CHECK-NEXT: [[ABS:%.*]] = call <4 x i32> @llvm.abs.v4i32(<4 x i32> [[AND]], i1 false) ; CHECK-NEXT: [[AND2:%.*]] = and <4 x i32> [[ABS]], <i32 -4, i32 -4, i32 -4, i32 -4> ; CHECK-NEXT: ret <4 x i32> [[AND2]] ; %and = and <4 x i32> %x, <i32 -2, i32 -2, i32 -2, i32 -2> %abs = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %and, i1 false) %and2 = and <4 x i32> %abs, <i32 -4, i32 -4, i32 -4, i32 -4> ret <4 x i32> %and2 } ; Make sure we infer this add doesn't overflow. The input to the abs has 3 ; sign bits, the abs reduces this to 2 sign bits. define i32 @abs_signbits(i30 %x) { ; CHECK-LABEL: @abs_signbits( ; CHECK-NEXT: [[TMP1:%.*]] = call i30 @llvm.abs.i30(i30 [[X:%.*]], i1 false) ; CHECK-NEXT: [[NARROW:%.*]] = add nuw i30 [[TMP1]], 1 ; CHECK-NEXT: [[ADD:%.*]] = zext i30 [[NARROW]] to i32 ; CHECK-NEXT: ret i32 [[ADD]] ; %ext = sext i30 %x to i32 %abs = call i32 @llvm.abs.i32(i32 %ext, i1 false) %add = add i32 %abs, 1 ret i32 %add } define <4 x i32> @abs_signbits_vec(<4 x i30> %x) { ; CHECK-LABEL: @abs_signbits_vec( ; CHECK-NEXT: [[TMP1:%.*]] = call <4 x i30> @llvm.abs.v4i30(<4 x i30> [[X:%.*]], i1 false) ; CHECK-NEXT: [[NARROW:%.*]] = add nuw <4 x i30> [[TMP1]], <i30 1, i30 1, i30 1, i30 1> ; CHECK-NEXT: [[ADD:%.*]] = zext <4 x i30> [[NARROW]] to <4 x i32> ; CHECK-NEXT: ret <4 x i32> [[ADD]] ; %ext = sext <4 x i30> %x to <4 x i32> %abs = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %ext, i1 false) %add = add <4 x i32> %abs, <i32 1, i32 1, i32 1, i32 1> ret <4 x i32> %add } define i32 @abs_of_neg(i32 %x) { ; CHECK-LABEL: @abs_of_neg( ; CHECK-NEXT: [[B:%.*]] = call i32 @llvm.abs.i32(i32 [[X:%.*]], i1 false) ; CHECK-NEXT: ret i32 [[B]] ; %a = sub i32 0, %x %b = call i32 @llvm.abs.i32(i32 %a, i1 false) ret i32 %b } define <4 x i32> @abs_of_neg_vec(<4 x i32> %x) { ; CHECK-LABEL: @abs_of_neg_vec( ; CHECK-NEXT: [[B:%.*]] = call <4 x i32> @llvm.abs.v4i32(<4 x i32> [[X:%.*]], i1 false) ; CHECK-NEXT: ret <4 x i32> [[B]] ; %a = sub nsw <4 x i32> zeroinitializer, %x %b = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %a, i1 false) ret <4 x i32> %b } define i32 @abs_of_select_neg_true_val(i1 %b, i32 %x) { ; CHECK-LABEL: @abs_of_select_neg_true_val( ; CHECK-NEXT: [[ABS:%.*]] = call i32 @llvm.abs.i32(i32 [[X:%.*]], i1 true) ; CHECK-NEXT: ret i32 [[ABS]] ; %neg = sub i32 0, %x %sel = select i1 %b, i32 %neg, i32 %x %abs = call i32 @llvm.abs.i32(i32 %sel, i1 true) ret i32 %abs } define <4 x i32> @abs_of_select_neg_false_val(<4 x i1> %b, <4 x i32> %x) { ; CHECK-LABEL: @abs_of_select_neg_false_val( ; CHECK-NEXT: [[ABS:%.*]] = call <4 x i32> @llvm.abs.v4i32(<4 x i32> [[X:%.*]], i1 false) ; CHECK-NEXT: ret <4 x i32> [[ABS]] ; %neg = sub <4 x i32> zeroinitializer, %x %sel = select <4 x i1> %b, <4 x i32> %x, <4 x i32> %neg %abs = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %sel, i1 false) ret <4 x i32> %abs } define i32 @abs_dom_cond_nopoison(i32 %x) { ; CHECK-LABEL: @abs_dom_cond_nopoison( ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[X:%.*]], -1 ; CHECK-NEXT: br i1 [[CMP]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: ret i32 [[X]] ; CHECK: false: ; CHECK-NEXT: [[A2:%.*]] = sub i32 0, [[X]] ; CHECK-NEXT: ret i32 [[A2]] ; %cmp = icmp sge i32 %x, 0 br i1 %cmp, label %true, label %false true: %a1 = call i32 @llvm.abs.i32(i32 %x, i1 false) ret i32 %a1 false: %a2 = call i32 @llvm.abs.i32(i32 %x, i1 false) ret i32 %a2 } define i32 @abs_dom_cond_poison(i32 %x) { ; CHECK-LABEL: @abs_dom_cond_poison( ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[X:%.*]], -1 ; CHECK-NEXT: br i1 [[CMP]], label [[TRUE:%.*]], label [[FALSE:%.*]] ; CHECK: true: ; CHECK-NEXT: ret i32 [[X]] ; CHECK: false: ; CHECK-NEXT: [[A2:%.*]] = sub nsw i32 0, [[X]] ; CHECK-NEXT: ret i32 [[A2]] ; %cmp = icmp sge i32 %x, 0 br i1 %cmp, label %true, label %false true: %a1 = call i32 @llvm.abs.i32(i32 %x, i1 true) ret i32 %a1 false: %a2 = call i32 @llvm.abs.i32(i32 %x, i1 true) ret i32 %a2 } ; Abs argument non-neg based on known bits. define i32 @zext_abs(i31 %x) { ; CHECK-LABEL: @zext_abs( ; CHECK-NEXT: [[ZEXT:%.*]] = zext i31 [[X:%.*]] to i32 ; CHECK-NEXT: ret i32 [[ZEXT]] ; %zext = zext i31 %x to i32 %abs = call i32 @llvm.abs.i32(i32 %zext, i1 false) ret i32 %abs } define <3 x i82> @lshr_abs(<3 x i82> %x) { ; CHECK-LABEL: @lshr_abs( ; CHECK-NEXT: [[LSHR:%.*]] = lshr <3 x i82> [[X:%.*]], <i82 1, i82 1, i82 1> ; CHECK-NEXT: ret <3 x i82> [[LSHR]] ; %lshr = lshr <3 x i82> %x, <i82 1, i82 1, i82 1> %abs = call <3 x i82> @llvm.abs.v3i82(<3 x i82> %lshr, i1 true) ret <3 x i82> %abs } define i32 @and_abs(i32 %x) { ; CHECK-LABEL: @and_abs( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 2147483644 ; CHECK-NEXT: ret i32 [[AND]] ; %and = and i32 %x, 2147483644 %abs = call i32 @llvm.abs.i32(i32 %and, i1 true) ret i32 %abs } define <3 x i82> @select_abs(<3 x i1> %cond) { ; CHECK-LABEL: @select_abs( ; CHECK-NEXT: [[SEL:%.*]] = select <3 x i1> [[COND:%.*]], <3 x i82> zeroinitializer, <3 x i82> <i82 2147483647, i82 42, i82 1> ; CHECK-NEXT: ret <3 x i82> [[SEL]] ; %sel = select <3 x i1> %cond, <3 x i82> zeroinitializer, <3 x i82> <i82 2147483647, i82 42, i82 1> %abs = call <3 x i82> @llvm.abs.v3i82(<3 x i82> %sel, i1 false) ret <3 x i82> %abs } define i32 @assume_abs(i32 %x) { ; CHECK-LABEL: @assume_abs( ; CHECK-NEXT: [[ASSUME:%.*]] = icmp sgt i32 [[X:%.*]], -1 ; CHECK-NEXT: call void @llvm.assume(i1 [[ASSUME]]) ; CHECK-NEXT: ret i32 [[X]] ; %assume = icmp sge i32 %x, 0 call void @llvm.assume(i1 %assume) %abs = call i32 @llvm.abs.i32(i32 %x, i1 true) ret i32 %abs } ; Abs argument negative based on known bits. define i32 @abs_assume_neg(i32 %x) { ; CHECK-LABEL: @abs_assume_neg( ; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[X:%.*]], 0 ; CHECK-NEXT: call void @llvm.assume(i1 [[CMP]]) ; CHECK-NEXT: [[ABS:%.*]] = sub i32 0, [[X]] ; CHECK-NEXT: ret i32 [[ABS]] ; %cmp = icmp slt i32 %x, 0 call void @llvm.assume(i1 %cmp) %abs = call i32 @llvm.abs.i32(i32 %x, i1 false) ret i32 %abs } define i32 @abs_known_neg(i16 %x) { ; CHECK-LABEL: @abs_known_neg( ; CHECK-NEXT: [[EXT:%.*]] = zext i16 [[X:%.*]] to i32 ; CHECK-NEXT: [[NEG_NEG:%.*]] = add nuw nsw i32 [[EXT]], 1 ; CHECK-NEXT: ret i32 [[NEG_NEG]] ; %ext = zext i16 %x to i32 %neg = sub nsw i32 -1, %ext %abs = call i32 @llvm.abs.i32(i32 %neg, i1 false) ret i32 %abs } define i1 @abs_eq_int_min_poison(i8 %x) { ; CHECK-LABEL: @abs_eq_int_min_poison( ; CHECK-NEXT: ret i1 false ; %abs = call i8 @llvm.abs.i8(i8 %x, i1 true) %cmp = icmp eq i8 %abs, -128 ret i1 %cmp } define i1 @abs_ne_int_min_poison(i8 %x) { ; CHECK-LABEL: @abs_ne_int_min_poison( ; CHECK-NEXT: ret i1 true ; %abs = call i8 @llvm.abs.i8(i8 %x, i1 true) %cmp = icmp ne i8 %abs, -128 ret i1 %cmp } define i1 @abs_eq_int_min_nopoison(i8 %x) { ; CHECK-LABEL: @abs_eq_int_min_nopoison( ; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], -128 ; CHECK-NEXT: ret i1 [[CMP]] ; %abs = call i8 @llvm.abs.i8(i8 %x, i1 false) %cmp = icmp eq i8 %abs, -128 ret i1 %cmp } define i1 @abs_ne_int_min_nopoison(i8 %x) { ; CHECK-LABEL: @abs_ne_int_min_nopoison( ; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X:%.*]], -128 ; CHECK-NEXT: ret i1 [[CMP]] ; %abs = call i8 @llvm.abs.i8(i8 %x, i1 false) %cmp = icmp ne i8 %abs, -128 ret i1 %cmp } define i32 @abs_sext(i8 %x) { ; CHECK-LABEL: @abs_sext( ; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.abs.i8(i8 [[X:%.*]], i1 false) ; CHECK-NEXT: [[A:%.*]] = zext i8 [[TMP1]] to i32 ; CHECK-NEXT: ret i32 [[A]] ; %s = sext i8 %x to i32 %a = call i32 @llvm.abs.i32(i32 %s, i1 0) ret i32 %a } define <3 x i82> @abs_nsw_sext(<3 x i7> %x) { ; CHECK-LABEL: @abs_nsw_sext( ; CHECK-NEXT: [[TMP1:%.*]] = call <3 x i7> @llvm.abs.v3i7(<3 x i7> [[X:%.*]], i1 false) ; CHECK-NEXT: [[A:%.*]] = zext <3 x i7> [[TMP1]] to <3 x i82> ; CHECK-NEXT: ret <3 x i82> [[A]] ; %s = sext <3 x i7> %x to <3 x i82> %a = call <3 x i82> @llvm.abs.v3i82(<3 x i82> %s, i1 1) ret <3 x i82> %a } define i32 @abs_sext_extra_use(i8 %x, i32* %p) { ; CHECK-LABEL: @abs_sext_extra_use( ; CHECK-NEXT: [[S:%.*]] = sext i8 [[X:%.*]] to i32 ; CHECK-NEXT: store i32 [[S]], i32* [[P:%.*]], align 4 ; CHECK-NEXT: [[A:%.*]] = call i32 @llvm.abs.i32(i32 [[S]], i1 false) ; CHECK-NEXT: ret i32 [[A]] ; %s = sext i8 %x to i32 store i32 %s, i32* %p %a = call i32 @llvm.abs.i32(i32 %s, i1 0) ret i32 %a } ; PR48816 define i8 @trunc_abs_sext(i8 %x) { ; CHECK-LABEL: @trunc_abs_sext( ; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.abs.i8(i8 [[X:%.*]], i1 false) ; CHECK-NEXT: ret i8 [[TMP1]] ; %s = sext i8 %x to i32 %a = tail call i32 @llvm.abs.i32(i32 %s, i1 true) %t = trunc i32 %a to i8 ret i8 %t } define <4 x i8> @trunc_abs_sext_vec(<4 x i8> %x) { ; CHECK-LABEL: @trunc_abs_sext_vec( ; CHECK-NEXT: [[TMP1:%.*]] = call <4 x i8> @llvm.abs.v4i8(<4 x i8> [[X:%.*]], i1 false) ; CHECK-NEXT: ret <4 x i8> [[TMP1]] ; %s = sext <4 x i8> %x to <4 x i32> %a = tail call <4 x i32> @llvm.abs.v4i32(<4 x i32> %s, i1 true) %t = trunc <4 x i32> %a to <4 x i8> ret <4 x i8> %t } ; abs() doesn't change the low bit. define i32 @demand_low_bit(i32 %x) { ; CHECK-LABEL: @demand_low_bit( ; CHECK-NEXT: [[R:%.*]] = and i32 [[X:%.*]], 1 ; CHECK-NEXT: ret i32 [[R]] ; %a = call i32 @llvm.abs.i32(i32 %x, i1 false) %r = and i32 %a, 1 ret i32 %r } ; Int min behavior doesn't affect the transform. define <3 x i82> @demand_low_bit_int_min_is_poison(<3 x i82> %x) { ; CHECK-LABEL: @demand_low_bit_int_min_is_poison( ; CHECK-NEXT: [[R:%.*]] = shl <3 x i82> [[X:%.*]], <i82 81, i82 81, i82 81> ; CHECK-NEXT: ret <3 x i82> [[R]] ; %a = call <3 x i82> @llvm.abs.v3i82(<3 x i82> %x, i1 true) %r = shl <3 x i82> %a, <i82 81, i82 81, i82 81> ret <3 x i82> %r } ; Negative test - only low bit is allowed. define i32 @demand_low_bits(i32 %x) { ; CHECK-LABEL: @demand_low_bits( ; CHECK-NEXT: [[A:%.*]] = call i32 @llvm.abs.i32(i32 [[X:%.*]], i1 false) ; CHECK-NEXT: [[R:%.*]] = and i32 [[A]], 3 ; CHECK-NEXT: ret i32 [[R]] ; %a = call i32 @llvm.abs.i32(i32 %x, i1 false) %r = and i32 %a, 3 ret i32 %r } define i32 @srem_by_2_int_min_is_poison(i32 %x) { ; CHECK-LABEL: @srem_by_2_int_min_is_poison( ; CHECK-NEXT: [[R:%.*]] = and i32 [[X:%.*]], 1 ; CHECK-NEXT: ret i32 [[R]] ; %s = srem i32 %x, 2 %r = call i32 @llvm.abs.i32(i32 %s, i1 true) ret i32 %r } define <3 x i82> @srem_by_2(<3 x i82> %x, <3 x i82>* %p) { ; CHECK-LABEL: @srem_by_2( ; CHECK-NEXT: [[S:%.*]] = srem <3 x i82> [[X:%.*]], <i82 2, i82 2, i82 2> ; CHECK-NEXT: store <3 x i82> [[S]], <3 x i82>* [[P:%.*]], align 32 ; CHECK-NEXT: [[R:%.*]] = and <3 x i82> [[X]], <i82 1, i82 1, i82 1> ; CHECK-NEXT: ret <3 x i82> [[R]] ; %s = srem <3 x i82> %x, <i82 2, i82 2, i82 2> store <3 x i82> %s, <3 x i82>* %p %r = call <3 x i82> @llvm.abs.v3i82(<3 x i82> %s, i1 false) ret <3 x i82> %r } ; TODO: A more general transform could sink the srem and turn it into urem. define i32 @srem_by_3(i32 %x) { ; CHECK-LABEL: @srem_by_3( ; CHECK-NEXT: [[S:%.*]] = srem i32 [[X:%.*]], 3 ; CHECK-NEXT: [[R:%.*]] = call i32 @llvm.abs.i32(i32 [[S]], i1 true) ; CHECK-NEXT: ret i32 [[R]] ; %s = srem i32 %x, 3 %r = call i32 @llvm.abs.i32(i32 %s, i1 true) ret i32 %r } ; Test from https://github.com/llvm/llvm-project/issues/54132. define i32 @sub_abs_gt(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_abs_gt( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[X]], [[Y]] ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[R:%.*]] = phi i32 [ [[SUB]], [[COND_TRUE]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[R]] ; entry: %cmp = icmp sgt i32 %x, %y br i1 %cmp, label %cond.true, label %cond.end cond.true: %sub = sub nsw i32 %x, %y %0 = call i32 @llvm.abs.i32(i32 %sub, i1 true) br label %cond.end cond.end: %r = phi i32 [ %0, %cond.true ], [ 0, %entry ] ret i32 %r } define i32 @sub_abs_lt(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_abs_lt( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[SUB_NEG:%.*]] = sub i32 [[Y]], [[X]] ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[R:%.*]] = phi i32 [ [[SUB_NEG]], [[COND_TRUE]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[R]] ; entry: %cmp = icmp slt i32 %x, %y br i1 %cmp, label %cond.true, label %cond.end cond.true: %sub = sub nsw i32 %x, %y %0 = call i32 @llvm.abs.i32(i32 %sub, i1 true) br label %cond.end cond.end: %r = phi i32 [ %0, %cond.true ], [ 0, %entry ] ret i32 %r } define i32 @sub_abs_lt_min_not_poison(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_abs_lt_min_not_poison( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[SUB_NEG:%.*]] = sub i32 [[Y]], [[X]] ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[R:%.*]] = phi i32 [ [[SUB_NEG]], [[COND_TRUE]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[R]] ; entry: %cmp = icmp slt i32 %x, %y br i1 %cmp, label %cond.true, label %cond.end cond.true: %sub = sub nsw i32 %x, %y %0 = call i32 @llvm.abs.i32(i32 %sub, i1 false) br label %cond.end cond.end: %r = phi i32 [ %0, %cond.true ], [ 0, %entry ] ret i32 %r } define i32 @sub_abs_wrong_pred(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_abs_wrong_pred( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[SUB:%.*]] = sub nsw i32 [[X]], [[Y]] ; CHECK-NEXT: [[TMP0:%.*]] = call i32 @llvm.abs.i32(i32 [[SUB]], i1 true) ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[R:%.*]] = phi i32 [ [[TMP0]], [[COND_TRUE]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[R]] ; entry: %cmp = icmp ugt i32 %x, %y br i1 %cmp, label %cond.true, label %cond.end cond.true: %sub = sub nsw i32 %x, %y %0 = call i32 @llvm.abs.i32(i32 %sub, i1 true) br label %cond.end cond.end: %r = phi i32 [ %0, %cond.true ], [ 0, %entry ] ret i32 %r } define i32 @sub_abs_no_nsw(i32 %x, i32 %y) { ; CHECK-LABEL: @sub_abs_no_nsw( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[X:%.*]], [[Y:%.*]] ; CHECK-NEXT: br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[SUB:%.*]] = sub i32 [[X]], [[Y]] ; CHECK-NEXT: [[TMP0:%.*]] = call i32 @llvm.abs.i32(i32 [[SUB]], i1 true) ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[R:%.*]] = phi i32 [ [[TMP0]], [[COND_TRUE]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: ret i32 [[R]] ; entry: %cmp = icmp sgt i32 %x, %y br i1 %cmp, label %cond.true, label %cond.end cond.true: %sub = sub i32 %x, %y %0 = call i32 @llvm.abs.i32(i32 %sub, i1 true) br label %cond.end cond.end: %r = phi i32 [ %0, %cond.true ], [ 0, %entry ] ret i32 %r }