[llvm] r231948 - InstCombine: Don't fold call bitcast into args if callee is byval

[David Majnemer]

Author: majnemer
Date: Wed Mar 11 13:03:05 2015
New Revision: 231948

URL: http://llvm.org/viewvc/llvm-project?rev=231948&view=rev
Log:
InstCombine: Don't fold call bitcast into args if callee is byval

This fixes a bug reported here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150309/265341.html

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
    llvm/trunk/test/Transforms/InstCombine/call-cast-target.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=231948&r1=231947&r2=231948&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Wed Mar 11 13:03:05 2015
@@ -1485,7 +1485,10 @@ bool InstCombiner::transformConstExprCas
   //
   // into:
   //  call void @takes_i32_inalloca(i32* null)
-  if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca))
+  //
+  //  Similarly, avoid folding away bitcasts of byval calls.
+  if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca) ||
+      Callee->getAttributes().hasAttrSomewhere(Attribute::ByVal))
     return false;
 
   CallSite::arg_iterator AI = CS.arg_begin();

Modified: llvm/trunk/test/Transforms/InstCombine/call-cast-target.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/call-cast-target.ll?rev=231948&r1=231947&r2=231948&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/call-cast-target.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/call-cast-target.ll Wed Mar 11 13:03:05 2015
@@ -72,3 +72,18 @@ entry:
   %call = tail call i32 bitcast (i32 (i32)* @fn4 to i32 (i32*)*)(i32* %a)
   ret i32 %call
 }
+
+declare i1 @fn5({ i32, i32 }* byval align 4 %r)
+
+define i1 @test5() {
+; CHECK-LABEL: @test5
+; CHECK:      %[[call:.*]] = call i1 bitcast (i1 ({ i32, i32 }*)* @fn5 to i1 (i32, i32)*)(i32 {{.*}}, i32 {{.*}})
+; CHECK-NEXT: ret i1 %[[call]]
+  %1 = alloca { i32, i32 }, align 4
+  %2 = getelementptr inbounds { i32, i32 }, { i32, i32 }* %1, i32 0, i32 0
+  %3 = load i32, i32* %2, align 4
+  %4 = getelementptr inbounds { i32, i32 }, { i32, i32 }* %1, i32 0, i32 1
+  %5 = load i32, i32* %4, align 4
+  %6 = call i1 bitcast (i1 ({ i32, i32 }*)* @fn5 to i1 (i32, i32)*)(i32 %3, i32 %5)
+  ret i1 %6
+}