forked from OSchip/llvm-project
37 lines
1.6 KiB
LLVM
37 lines
1.6 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -simplifycfg -S | FileCheck %s
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; RUN: opt < %s -simplifycfg -phi-node-folding-threshold=2 -S | FileCheck %s
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; RUN: opt < %s -simplifycfg -phi-node-folding-threshold=3 -S | FileCheck %s
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; This is checking that the multiplication does overflow, with a leftover
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; guard against division-by-zero that was needed before InstCombine
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; produced llvm.umul.with.overflow.
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define i1 @will_overflow(i64 %size, i64 %nmemb) {
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; CHECK-LABEL: @will_overflow(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[SIZE:%.*]], 0
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; CHECK-NEXT: [[UMUL:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[SIZE]], i64 [[NMEMB:%.*]])
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; CHECK-NEXT: [[UMUL_OV:%.*]] = extractvalue { i64, i1 } [[UMUL]], 1
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; CHECK-NEXT: [[UMUL_NOT_OV:%.*]] = xor i1 [[UMUL_OV]], true
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; CHECK-NEXT: [[TMP0:%.*]] = select i1 [[CMP]], i1 true, i1 [[UMUL_NOT_OV]]
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; CHECK-NEXT: ret i1 [[TMP0]]
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;
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entry:
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%cmp = icmp eq i64 %size, 0
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br i1 %cmp, label %land.end, label %land.rhs
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land.rhs: ; preds = %entry
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%umul = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %size, i64 %nmemb)
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%umul.ov = extractvalue { i64, i1 } %umul, 1
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%umul.not.ov = xor i1 %umul.ov, true
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br label %land.end
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land.end: ; preds = %land.rhs, %entry
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%0 = phi i1 [ true, %entry ], [ %umul.not.ov, %land.rhs ]
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ret i1 %0
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}
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; Function Attrs: nounwind readnone speculatable
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declare { i64, i1 } @llvm.umul.with.overflow.i64(i64, i64) #0
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