[llvm-commits] [llvm] r122172 - in /llvm/trunk: lib/Transforms/Scalar/LICM.cpp test/Transforms/LICM/scalar_promote.ll

[Chris Lattner]

Author: lattner
Date: Sat Dec 18 23:57:25 2010
New Revision: 122172

URL: http://llvm.org/viewvc/llvm-project?rev=122172&view=rev
Log:
Enhance LICM to promote alias sets whose pointers themselves are stored,
which doesn't affect the memory address being promoted.

Modified:
    llvm/trunk/lib/Transforms/Scalar/LICM.cpp
    llvm/trunk/test/Transforms/LICM/scalar_promote.ll

Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=122172&r1=122171&r2=122172&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Sat Dec 18 23:57:25 2010
@@ -691,7 +691,10 @@
       if (isa<LoadInst>(Use))
         assert(!cast<LoadInst>(Use)->isVolatile() && "AST broken");
       else if (isa<StoreInst>(Use)) {
-        if (Use->getOperand(0) == ASIV) return;
+        // Stores *of* the pointer are not interesting, only stores *to* the
+        // pointer.
+        if (Use->getOperand(1) != ASIV)
+          continue;
         assert(!cast<StoreInst>(Use)->isVolatile() && "AST broken");
       } else
         return; // Not a load or store.

Modified: llvm/trunk/test/Transforms/LICM/scalar_promote.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LICM/scalar_promote.ll?rev=122172&r1=122171&r2=122172&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LICM/scalar_promote.ll (original)
+++ llvm/trunk/test/Transforms/LICM/scalar_promote.ll Sat Dec 18 23:57:25 2010
@@ -118,3 +118,33 @@
   ret void
 }
 
+define void @test5(i32 %i, i32** noalias %P2) {
+Entry:
+	br label %Loop
+; CHECK: @test5
+; CHECK: Entry:
+; CHECK-NEXT:   load i32* @X
+; CHECK-NEXT:   br label %Loop
+
+
+Loop:		; preds = %Loop, %0
+	%j = phi i32 [ 0, %Entry ], [ %Next, %Loop ]		; <i32> [#uses=1]
+	%x = load i32* @X		; <i32> [#uses=1]
+	%x2 = add i32 %x, 1		; <i32> [#uses=1]
+	store i32 %x2, i32* @X
+        
+        volatile store i32* @X, i32** %P2
+        
+	%Next = add i32 %j, 1		; <i32> [#uses=2]
+	%cond = icmp eq i32 %Next, 0		; <i1> [#uses=1]
+	br i1 %cond, label %Out, label %Loop
+
+Out:	
+	ret void
+; CHECK: Out:
+; CHECK-NEXT:   store i32 %x2, i32* @X
+; CHECK-NEXT:   ret void
+
+}
+
+