[llvm-commits] [llvm] r131897 - in /llvm/trunk: lib/Analysis/BasicAliasAnalysis.cpp test/Transforms/DeadStoreElimination/simple.ll

[Chris Lattner]

Author: lattner
Date: Mon May 23 00:15:43 2011
New Revision: 131897

URL: http://llvm.org/viewvc/llvm-project?rev=131897&view=rev
Log:
fix a really nasty basicaa mod/ref calculation bug that was causing miscompilation of
UnitTests/ObjC/messages-2.m with the recent optimizer improvements.

Modified:
    llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
    llvm/trunk/test/Transforms/DeadStoreElimination/simple.ll

Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=131897&r1=131896&r2=131897&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Mon May 23 00:15:43 2011
@@ -680,9 +680,12 @@
     unsigned ArgNo = 0;
     for (ImmutableCallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
          CI != CE; ++CI, ++ArgNo) {
-      // Only look at the no-capture pointer arguments.
+      // Only look at the no-capture or byval pointer arguments.  If this
+      // pointer were passed to arguments that were neither of these, then it
+      // couldn't be no-capture.
       if (!(*CI)->getType()->isPointerTy() ||
-          !CS.paramHasAttr(ArgNo+1, Attribute::NoCapture))
+          (!CS.paramHasAttr(ArgNo+1, Attribute::NoCapture) &&
+           !CS.paramHasAttr(ArgNo+1, Attribute::ByVal)))
         continue;
       
       // If this is a no-capture pointer argument, see if we can tell that it

Modified: llvm/trunk/test/Transforms/DeadStoreElimination/simple.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/simple.ll?rev=131897&r1=131896&r2=131897&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/simple.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/simple.ll Mon May 23 00:15:43 2011
@@ -236,3 +236,20 @@
 ; CHECK-NEXT: call void @llvm.memcpy
 ; CHECK-NEXT: ret
 }
+
+
+; The store here is not dead because the byval call reads it.
+declare void @test19f({i32}* byval align 4 %P)
+
+define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp {
+bb:
+  %tmp7 = getelementptr inbounds {i32}* %arg5, i32 0, i32 0
+  store i32 912, i32* %tmp7
+  call void @test19f({i32}* byval align 4 %arg5)
+  ret void
+
+; CHECK: @test19(
+; CHECK: store i32 912
+; CHECK: call void @test19f
+}
+