[MSan] Handle llvm.is.constant intrinsic
MSan used to report false positives in the case the argument of llvm.is.constant intrinsic was uninitialized. In fact checking this argument is unnecessary, as the intrinsic is only used at compile time, and its value doesn't depend on the value of the argument. llvm-svn: 350173
This commit is contained in:
parent
802c4979ae
commit
cea4f83371
|
@ -3099,6 +3099,12 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
|
|||
handleVectorComparePackedIntrinsic(I);
|
||||
break;
|
||||
|
||||
case Intrinsic::is_constant:
|
||||
// The result of llvm.is.constant() is always defined.
|
||||
setShadow(&I, getCleanShadow(&I));
|
||||
setOrigin(&I, getCleanOrigin());
|
||||
break;
|
||||
|
||||
default:
|
||||
if (!handleUnknownIntrinsic(I))
|
||||
visitInstruction(I);
|
||||
|
|
|
@ -0,0 +1,21 @@
|
|||
; Make sure MSan doesn't insert shadow checks for @llvm.is.constant.* arguments.
|
||||
|
||||
; RUN: opt < %s -msan -msan-kernel=1 -S | FileCheck -check-prefixes=CHECK %s
|
||||
; RUN: opt < %s -msan -S | FileCheck -check-prefixes=CHECK %s
|
||||
|
||||
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
|
||||
target triple = "x86_64-unknown-linux-gnu"
|
||||
|
||||
; Function Attrs: nounwind readnone uwtable
|
||||
define dso_local i32 @bar(i32 %v) local_unnamed_addr sanitize_memory {
|
||||
entry:
|
||||
%0 = tail call i1 @llvm.is.constant.i32(i32 %v)
|
||||
%1 = zext i1 %0 to i32
|
||||
ret i32 %1
|
||||
}
|
||||
|
||||
; CHECK-LABEL: bar
|
||||
; CHECK-NOT: call void @__msan_warning
|
||||
|
||||
; Function Attrs: nounwind readnone
|
||||
declare i1 @llvm.is.constant.i32(i32)
|
Loading…
Reference in New Issue