[llvm-commits] [llvm] r44279 - in /llvm/trunk: lib/Analysis/BasicAliasAnalysis.cpp test/Analysis/BasicAA/pure-const-dce.ll

[Duncan Sands]

Author: baldrick
Date: Thu Nov 22 15:43:27 2007
New Revision: 44279

URL: http://llvm.org/viewvc/llvm-project?rev=44279&view=rev
Log:
Teach alias analysis about readnone/readonly functions.
Based on a patch by Török Edwin.

Added:
    llvm/trunk/test/Analysis/BasicAA/pure-const-dce.ll
Modified:
    llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp

Modified: llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp?rev=44279&r1=44278&r2=44279&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/BasicAliasAnalysis.cpp Thu Nov 22 15:43:27 2007
@@ -952,6 +952,12 @@
   if (Ptr != OnlyReadsMemoryTable->end() && strcmp(*Ptr, NamePtr) == 0)
     return OnlyReadsMemory;
 
+  const ParamAttrsList *Attrs = F->getFunctionType()->getParamAttrs();
+  if (Attrs && Attrs->paramHasAttr(0, ParamAttr::ReadNone))
+    return DoesNotAccessMemory;
+  if (Attrs && Attrs->paramHasAttr(0, ParamAttr::ReadOnly))
+    return OnlyReadsMemory;
+
   return UnknownModRefBehavior;
 }
 

Added: llvm/trunk/test/Analysis/BasicAA/pure-const-dce.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/BasicAA/pure-const-dce.ll?rev=44279&view=auto

==============================================================================
--- llvm/trunk/test/Analysis/BasicAA/pure-const-dce.ll (added)
+++ llvm/trunk/test/Analysis/BasicAA/pure-const-dce.ll Thu Nov 22 15:43:27 2007
@@ -0,0 +1,33 @@
+; RUN: llvm-as < %s | opt -basicaa -gvn | llvm-dis | grep TestConst | count 2
+; RUN: llvm-as < %s | opt -basicaa -gvn | llvm-dis | grep TestPure  | not count 2
+; RUN: llvm-as < %s | opt -basicaa -gvn | llvm-dis | grep TestNone  | count 4
+ at g = global i32 0		; <i32*> [#uses=1]
+
+define i32 @test() {
+entry:
+	%tmp0 = call i32 @TestConst( i32 5 ) readnone 		; <i32> [#uses=1]
+	%tmp1 = call i32 @TestPure( i32 6 ) readonly 		; <i32> [#uses=1]
+	%tmp2 = call i32 @TestNone( i32 7 )		; <i32> [#uses=1]
+	store i32 1, i32* @g
+	%tmp3 = call i32 @TestConst( i32 5 ) readnone 		; <i32> [#uses=1]
+	%tmp4 = call i32 @TestConst( i32 5 ) readnone 		; <i32> [#uses=1]
+	%tmp5 = call i32 @TestPure( i32 6 ) readonly 		; <i32> [#uses=1]
+	%tmp6 = call i32 @TestPure( i32 6 ) readonly 		; <i32> [#uses=1]
+	%tmp7 = call i32 @TestNone( i32 7 )		; <i32> [#uses=1]
+	%tmp8 = call i32 @TestNone( i32 7 )		; <i32> [#uses=1]
+	%sum0 = add i32 %tmp0, %tmp1		; <i32> [#uses=1]
+	%sum1 = add i32 %sum0, %tmp2		; <i32> [#uses=1]
+	%sum2 = add i32 %sum1, %tmp3		; <i32> [#uses=1]
+	%sum3 = add i32 %sum2, %tmp4		; <i32> [#uses=1]
+	%sum4 = add i32 %sum3, %tmp5		; <i32> [#uses=1]
+	%sum5 = add i32 %sum4, %tmp6		; <i32> [#uses=1]
+	%sum6 = add i32 %sum5, %tmp7		; <i32> [#uses=1]
+	%sum7 = add i32 %sum6, %tmp8		; <i32> [#uses=1]
+	ret i32 %sum7
+}
+
+declare i32 @TestConst(i32) readnone
+
+declare i32 @TestPure(i32) readonly
+
+declare i32 @TestNone(i32)