Commit 9af1b339 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r326521: 

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r326521 | indutny | 2018-03-01 16:59:27 -0800 (Thu, 01 Mar 2018) | 13 lines

[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
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llvm-svn: 329858
parent 2bc42eb1

llvm/lib/Transforms/IPO/ArgumentPromotion.cpp

+10 −0
Original line number Diff line number Diff line
@@ -847,10 +847,20 @@ promoteArguments(Function *F, function_ref<AAResults &(Function &F)> AARGetter, 
    if (CS.getInstruction() == nullptr || !CS.isCallee(&U))

      return nullptr;



    // Can't change signature of musttail callee

    if (CS.isMustTailCall())

      return nullptr;



    if (CS.getInstruction()->getParent()->getParent() == F)

      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();



  AAResults &AAR = AARGetter(*F);

llvm/test/Transforms/ArgumentPromotion/musttail.ll

0 → 100644
+45 −0
Original line number Diff line number Diff line 
; 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

}