[llvm-commits] [llvm] r71077 - in /llvm/trunk: lib/Transforms/IPO/FunctionAttrs.cpp test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll

[Duncan Sands]

Author: baldrick
Date: Wed May  6 03:42:00 2009
New Revision: 71077

URL: http://llvm.org/viewvc/llvm-project?rev=71077&view=rev
Log:
Fix PR3754: don't mark functions that wrap MallocInst with
the readnone.  Since MallocInst is scheduled for deletion
it doesn't seem worth doing anything more subtle, such as
having mayWriteToMemory return true for MallocInst.

Added:
    llvm/trunk/test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll
Modified:
    llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp

Modified: llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp?rev=71077&r1=71076&r2=71077&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp Wed May  6 03:42:00 2009
@@ -152,6 +152,11 @@
       if (I->mayWriteToMemory())
         // Writes memory.  Just give up.
         return false;
+
+      if (isa<MallocInst>(I))
+        // MallocInst claims not to write memory!  PR3754.
+        return false;
+
       // If this instruction may read memory, remember that.
       ReadsMemory |= I->mayReadFromMemory();
     }

Added: llvm/trunk/test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll?rev=71077&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll (added)
+++ llvm/trunk/test/Transforms/FunctionAttrs/2009-05-06-Malloc.ll Wed May  6 03:42:00 2009
@@ -0,0 +1,7 @@
+; RUN: llvm-as < %s | opt -functionattrs | llvm-dis | not grep read
+; PR3754
+
+define i8* @m(i32 %size) {
+	%tmp = malloc i8, i32 %size		; <i8*> [#uses=1]
+	ret i8* %tmp
+}