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[ArgumentPromotion] don't break musttail invariant PR36543 

Summary:
Do not break musttail invariant by promoting arguments of musttail
callee or caller.

Reviewers: sanjoy, dberlin, hfinkel, george.burgess.iv, fhahn, rnk

Reviewed By: rnk

Subscribers: rnk, llvm-commits

Differential Revision: https://reviews.llvm.org/D43926

llvm-svn: 326521
This commit is contained in:
Fedor Indutny 2018-03-02 00:59:27 +00:00
parent 0ffcaf7437
commit 1571b1271e
2 changed files with 55 additions and 0 deletions
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10
llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
View File

@ -853,10 +853,20 @@ promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter,
if (CS.getInstruction() == nullptr || !CS.isCallee(&U)) if (CS.getInstruction() == nullptr || !CS.isCallee(&U))
return nullptr; return nullptr;
// Can't change signature of musttail callee
if (CS.isMustTailCall())
return nullptr;
if (CS.getInstruction()->getParent()->getParent() == F) if (CS.getInstruction()->getParent()->getParent() == F)
isSelfRecursive = true; isSelfRecursive = true;
} }
// Can't change signature of musttail caller
// FIXME: Support promoting whole chain of musttail functions
for (BasicBlock &BB : *F)
if (BB.getTerminatingMustTailCall())
return nullptr;
const DataLayout &DL = F->getParent()->getDataLayout(); const DataLayout &DL = F->getParent()->getDataLayout();
AAResults &AAR = AARGetter(*F); AAResults &AAR = AARGetter(*F);

45
llvm/test/Transforms/ArgumentPromotion/musttail.ll Normal file
View File

@ -0,0 +1,45 @@
; RUN: opt < %s -argpromotion -S | FileCheck %s
; PR36543
; Don't promote arguments of musttail callee
%T = type { i32, i32, i32, i32 }
; CHECK-LABEL: define internal i32 @test(%T* %p)
define internal i32 @test(%T* %p) {
%a.gep = getelementptr %T, %T* %p, i64 0, i32 3
%b.gep = getelementptr %T, %T* %p, i64 0, i32 2
%a = load i32, i32* %a.gep
%b = load i32, i32* %b.gep
%v = add i32 %a, %b
ret i32 %v
}
; CHECK-LABEL: define i32 @caller(%T* %p)
define i32 @caller(%T* %p) {
%v = musttail call i32 @test(%T* %p)
ret i32 %v
}
; Don't promote arguments of musttail caller
define i32 @foo(%T* %p, i32 %v) {
ret i32 0
}
; CHECK-LABEL: define internal i32 @test2(%T* %p, i32 %p2)
define internal i32 @test2(%T* %p, i32 %p2) {
%a.gep = getelementptr %T, %T* %p, i64 0, i32 3
%b.gep = getelementptr %T, %T* %p, i64 0, i32 2
%a = load i32, i32* %a.gep
%b = load i32, i32* %b.gep
%v = add i32 %a, %b
%ca = musttail call i32 @foo(%T* undef, i32 %v)
ret i32 %ca
}
; CHECK-LABEL: define i32 @caller2(%T* %g)
define i32 @caller2(%T* %g) {
%v = call i32 @test2(%T* %g, i32 0)
ret i32 %v
}