[llvm-commits] [llvm] r145865 - in /llvm/trunk: lib/Transforms/Scalar/MemCpyOptimizer.cpp test/Transforms/MemCpyOpt/form-memset.ll

[Chad Rosier]

Author: mcrosier
Date: Mon Dec  5 16:37:00 2011
New Revision: 145865

URL: http://llvm.org/viewvc/llvm-project?rev=145865&view=rev
Log:
Make the MemCpyOptimizer a bit more aggressive.  I can't think of a scenerio
where this would be bad as the backend shouldn't have a problem inlining small
memcpys.
rdar://10510150

Modified:
    llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
    llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll

Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=145865&r1=145864&r2=145865&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Mon Dec  5 16:37:00 2011
@@ -148,7 +148,7 @@
 
 bool MemsetRange::isProfitableToUseMemset(const TargetData &TD) const {
   // If we found more than 8 stores to merge or 64 bytes, use memset.
-  if (TheStores.size() >= 8 || End-Start >= 64) return true;
+  if (TheStores.size() >= 4 || End-Start >= 16) return true;
 
   // If there is nothing to merge, don't do anything.
   if (TheStores.size() < 2) return false;

Modified: llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll?rev=145865&r1=145864&r2=145865&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll (original)
+++ llvm/trunk/test/Transforms/MemCpyOpt/form-memset.ll Mon Dec  5 16:37:00 2011
@@ -57,8 +57,8 @@
 
 declare i32 @bar(...)
 
+%struct.MV = type { i16, i16 }
 
-	%struct.MV = type { i16, i16 }
 
 define void @test2() nounwind  {
 entry:
@@ -220,3 +220,19 @@
 ; CHECK: call void @llvm.memset.p0i8.i64(i8* %2, i8 0, i64 24, i32 1, i1 false)
 }
 
+; More aggressive heuristic
+; rdar://9892684
+define void @test7(i32* nocapture %c) nounwind optsize {
+  store i32 -1, i32* %c, align 4
+  %1 = getelementptr inbounds i32* %c, i32 1
+  store i32 -1, i32* %1, align 4
+  %2 = getelementptr inbounds i32* %c, i32 2
+  store i32 -1, i32* %2, align 4
+  %3 = getelementptr inbounds i32* %c, i32 3
+  store i32 -1, i32* %3, align 4
+  %4 = getelementptr inbounds i32* %c, i32 4
+  store i32 -1, i32* %4, align 4
+; CHECK: @test7
+; CHECK: call void @llvm.memset.p0i8.i64(i8* %5, i8 -1, i64 20, i32 4, i1 false)
+  ret void
+}