[llvm] r277969 - [SROA] Fix crash with lifetime intrinsic partially covering alloca.
Eli Friedman via llvm-commits
llvm-commits at lists.llvm.org
Sun Aug 7 18:30:54 PDT 2016
Author: efriedma
Date: Sun Aug 7 20:30:53 2016
New Revision: 277969
URL: http://llvm.org/viewvc/llvm-project?rev=277969&view=rev
Log:
[SROA] Fix crash with lifetime intrinsic partially covering alloca.
Summary:
PromoteMemToReg looks specifically for the pattern
bitcast+lifetime.start (or a bitcast-equivalent GEP); any offset
will lead to an assertion failure.
Fixes https://llvm.org/bugs/show_bug.cgi?id=27999 .
Differential Revision: https://reviews.llvm.org/D22737
Modified:
llvm/trunk/lib/Transforms/Scalar/SROA.cpp
llvm/trunk/test/Transforms/SROA/basictest.ll
Modified: llvm/trunk/lib/Transforms/Scalar/SROA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SROA.cpp?rev=277969&r1=277968&r2=277969&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SROA.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SROA.cpp Sun Aug 7 20:30:53 2016
@@ -2890,7 +2890,13 @@ private:
(void)New;
DEBUG(dbgs() << " to: " << *New << "\n");
- return true;
+
+ // Lifetime intrinsics are only promotable if they cover the whole alloca.
+ // (In theory, intrinsics which partially cover an alloca could be
+ // promoted, but PromoteMemToReg doesn't handle that case.)
+ bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
+ NewEndOffset == NewAllocaEndOffset;
+ return IsWholeAlloca;
}
bool visitPHINode(PHINode &PN) {
Modified: llvm/trunk/test/Transforms/SROA/basictest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SROA/basictest.ll?rev=277969&r1=277968&r2=277969&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SROA/basictest.ll (original)
+++ llvm/trunk/test/Transforms/SROA/basictest.ll Sun Aug 7 20:30:53 2016
@@ -1669,3 +1669,18 @@ entry:
}
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+define void @PR27999() unnamed_addr {
+; CHECK-LABEL: @PR27999(
+; CHECK: alloca [2 x i64], align 8
+; CHECK: call void @llvm.lifetime.start(i64 16,
+; CHECK: call void @llvm.lifetime.end(i64 8,
+entry-block:
+ %0 = alloca [2 x i64], align 8
+ %1 = bitcast [2 x i64]* %0 to i8*
+ call void @llvm.lifetime.start(i64 16, i8* %1)
+ %2 = getelementptr inbounds [2 x i64], [2 x i64]* %0, i32 0, i32 1
+ %3 = bitcast i64* %2 to i8*
+ call void @llvm.lifetime.end(i64 8, i8* %3)
+ ret void
+}
More information about the llvm-commits
mailing list