[llvm-commits] [llvm] r157129 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/2012-05-19-avx2-store.ll

[Nadav Rotem]

Author: nadav
Date: Sat May 19 15:30:08 2012
New Revision: 157129

URL: http://llvm.org/viewvc/llvm-project?rev=157129&view=rev
Log:
On Haswell, perfer storing YMM registers using a single instruction.

Added:
    llvm/trunk/test/CodeGen/X86/2012-05-19-avx2-store.ll
Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=157129&r1=157128&r2=157129&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sat May 19 15:30:08 2012
@@ -14532,13 +14532,12 @@
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
 
   // If we are saving a concatenation of two XMM registers, perform two stores.
-  // This is better in Sandy Bridge cause one 256-bit mem op is done via two
-  // 128-bit ones. If in the future the cost becomes only one memory access the
-  // first version would be better.
-  if (VT.getSizeInBits() == 256 &&
+  // On Sandy Bridge, 256-bit memory operations are executed by two
+  // 128-bit ports. However, on Haswell it is better to issue a single 256-bit
+  // memory  operation.
+  if (VT.getSizeInBits() == 256 && !Subtarget->hasAVX2() &&
       StoredVal.getNode()->getOpcode() == ISD::CONCAT_VECTORS &&
       StoredVal.getNumOperands() == 2) {
-
     SDValue Value0 = StoredVal.getOperand(0);
     SDValue Value1 = StoredVal.getOperand(1);
 

Added: llvm/trunk/test/CodeGen/X86/2012-05-19-avx2-store.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2012-05-19-avx2-store.ll?rev=157129&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2012-05-19-avx2-store.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2012-05-19-avx2-store.ll Sat May 19 15:30:08 2012
@@ -0,0 +1,14 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx -mattr=+avx2 | FileCheck %s
+
+define void @double_save(<4 x i32>* %Ap, <4 x i32>* %Bp, <8 x i32>* %P) nounwind ssp {
+entry:
+  ; CHECK: vmovaps
+  ; CHECK: vmovaps
+  ; CHECK: vinsertf128
+  ; CHECK: vmovups
+  %A = load <4 x i32>* %Ap
+  %B = load <4 x i32>* %Bp
+  %Z = shufflevector <4 x i32>%A, <4 x i32>%B, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+  store <8 x i32> %Z, <8 x i32>* %P, align 16
+  ret void
+}