Author: lattner
Date: Thu Dec 6 01:44:31 2007
New Revision: 44657
URL: http://llvm.org/viewvc/llvm-project?rev=44657&view=rev
Log:
Actually, disable this code for now. More analysis and improvements to
the X86 backend are needed before this should be enabled by default.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
llvm/trunk/test/CodeGen/X86/shift-combine.ll
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=44657&r1=44656&r2=44657&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Dec 6 01:44:31 2007
@@ -2134,6 +2134,12 @@
/// visitShiftByConstant - Handle transforms common to the three shifts, when
/// the shift amount is a constant.
SDOperand DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
+ // FIXME: disable this for now. This pessimizes some common cases like:
+ //
+ //void foo(int *X, int i) { X[i & 1235] = 1; }
+ //int bar(int *X, int i) { return X[i & 255]; }
+ return SDOperand();
+
SDNode *LHS = N->getOperand(0).Val;
if (!LHS->hasOneUse()) return SDOperand();
Modified: llvm/trunk/test/CodeGen/X86/shift-combine.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/shift-combine.ll?rev=44657&r1=44656&r2=44657&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/shift-combine.ll (original)
+++ llvm/trunk/test/CodeGen/X86/shift-combine.ll Thu Dec 6 01:44:31 2007
@@ -1,4 +1,5 @@
; RUN: llvm-as < %s | llc | not grep shrl
+; XFAIL: *
target datalayout =
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i686-apple-darwin8"
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
