[llvm-commits] [llvm] r51970 - in /llvm/trunk: lib/CodeGen/SelectionDAG/SelectionDAG.cpp test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll

[Evan Cheng]

Author: evancheng
Date: Wed Jun  4 18:37:54 2008
New Revision: 51970

URL: http://llvm.org/viewvc/llvm-project?rev=51970&view=rev
Log:
Fix a memcpy lowering bug. Even though the memcpy alignment is smaller than the desired alignment, the frame destination alignment may still be larger than the desired alignment. Don't change its alignment to something smaller.

Added:
    llvm/trunk/test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=51970&r1=51969&r2=51970&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Wed Jun  4 18:37:54 2008
@@ -2633,8 +2633,9 @@
           if (AllowUnalign)
             VT = MVT::iAny;
         } else {
-          // Give the stack frame object a larger alignment.
-          MFI->setObjectAlignment(FI, NewAlign);
+          // Give the stack frame object a larger alignment if needed.
+          if (MFI->getObjectAlignment(FI) < NewAlign)
+            MFI->setObjectAlignment(FI, NewAlign);
           Align = NewAlign;
         }
       }

Added: llvm/trunk/test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll?rev=51970&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2008-06-04-MemCpyLoweringBug.ll Wed Jun  4 18:37:54 2008
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -mattr=+sse2 -disable-fp-elim | grep subl | grep 24
+
+	%struct.argument_t = type { i8*, %struct.argument_t*, i32, %struct.ipc_type_t*, i32, void (...)*, void (...)*, void (...)*, void (...)*, void (...)*, i8*, i8*, i8*, i8*, i8*, i32, i32, i32, %struct.routine*, %struct.argument_t*, %struct.argument_t*, %struct.argument_t*, %struct.argument_t*, %struct.argument_t*, %struct.argument_t*, %struct.argument_t*, i32, i32, i32, i32, i32, i32 }
+	%struct.ipc_type_t = type { i8*, %struct.ipc_type_t*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8*, i8*, i32, i32, i32, i32, i32, i32, %struct.ipc_type_t*, i8*, i8*, i8*, i8*, i8*, i8*, i8*, i8* }
+	%struct.routine = type opaque
+@"\01LC" = external constant [11 x i8]		; <[11 x i8]*> [#uses=1]
+
+define i8* @InArgMsgField(%struct.argument_t* %arg, i8* %str) nounwind  {
+entry:
+	%who = alloca [20 x i8]		; <[20 x i8]*> [#uses=1]
+	%who1 = getelementptr [20 x i8]* %who, i32 0, i32 0		; <i8*> [#uses=2]
+	call void @llvm.memset.i32( i8* %who1, i8 0, i32 20, i32 1 )
+	call void @llvm.memcpy.i32( i8* %who1, i8* getelementptr ([11 x i8]* @"\01LC", i32 0, i32 0), i32 11, i32 1 )
+	unreachable
+}
+
+declare void @llvm.memset.i32(i8*, i8, i32, i32) nounwind 
+
+declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind