From 052dca5010cd6c855b453b3789bb2e99afb8cc83 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Sun, 8 Jun 2014 22:21:38 -0700
Subject: [PATCH] Const src1 permute.

---
 src/alloy/backend/x64/x64_sequences.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/alloy/backend/x64/x64_sequences.cc b/src/alloy/backend/x64/x64_sequences.cc
index 50981f1cb..a1bc716df 100644
--- a/src/alloy/backend/x64/x64_sequences.cc
+++ b/src/alloy/backend/x64/x64_sequences.cc
@@ -4497,7 +4497,12 @@ EMITTER(PERMUTE_V128, MATCH(I<OPCODE_PERMUTE, V128<>, V128<>, V128<>, V128<>>))
         e.vpxor(i.dest, i.dest);
       } else {
         // Control mask needs to be shuffled.
-        e.vpshufb(e.xmm0, i.src1, e.GetXmmConstPtr(XMMByteSwapMask));
+        if (i.src1.is_constant) {
+          e.LoadConstantXmm(e.xmm0, i.src1.constant());
+          e.vpshufb(e.xmm0, e.xmm0, e.GetXmmConstPtr(XMMByteSwapMask));
+        } else {
+          e.vpshufb(e.xmm0, i.src1, e.GetXmmConstPtr(XMMByteSwapMask));
+        }
         if (i.src2.is_constant) {
           e.LoadConstantXmm(i.dest, i.src2.constant());
           e.vpshufb(i.dest, i.dest, e.xmm0);