From e32342e956568128b620d0dd133145cb3e069938 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Tue, 27 May 2014 13:02:00 -0700
Subject: [PATCH] Variable vector_shl int8.

---
 src/alloy/backend/x64/x64_emitter.cc   |  1 +
 src/alloy/backend/x64/x64_emitter.h    |  1 +
 src/alloy/backend/x64/x64_sequences.cc | 36 +++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/alloy/backend/x64/x64_emitter.cc b/src/alloy/backend/x64/x64_emitter.cc
index aad925ef7..6e94a660a 100644
--- a/src/alloy/backend/x64/x64_emitter.cc
+++ b/src/alloy/backend/x64/x64_emitter.cc
@@ -443,6 +443,7 @@ Address X64Emitter::GetXmmConstPtr(XmmConst id) {
     /* XMMUnpackD3DCOLOR      */ vec128i(0xFFFFFF02, 0xFFFFFF01, 0xFFFFFF00, 0xFFFFFF02),
     /* XMMOneOver255          */ vec128f(1.0f / 255.0f, 1.0f / 255.0f, 1.0f / 255.0f, 1.0f / 255.0f),
     /* XMMShiftMaskPS         */ vec128i(0x0000001Fu, 0x0000001Fu, 0x0000001Fu, 0x0000001Fu),
+    /* XMMShiftByteMask       */ vec128i(0x000000FFu, 0x000000FFu, 0x000000FFu, 0x000000FFu),
   };
   // TODO(benvanik): cache base pointer somewhere? stack? It'd be nice to
   // prevent this move.
diff --git a/src/alloy/backend/x64/x64_emitter.h b/src/alloy/backend/x64/x64_emitter.h
index 7a36e3837..d67348e18 100644
--- a/src/alloy/backend/x64/x64_emitter.h
+++ b/src/alloy/backend/x64/x64_emitter.h
@@ -51,6 +51,7 @@ enum XmmConst {
   XMMUnpackD3DCOLOR     = 12,
   XMMOneOver255         = 13,
   XMMShiftMaskPS        = 14,
+  XMMShiftByteMask      = 15,
 };
 
 // Unfortunately due to the design of xbyak we have to pass this to the ctor.
diff --git a/src/alloy/backend/x64/x64_sequences.cc b/src/alloy/backend/x64/x64_sequences.cc
index 1a3f90abc..7f0850d6c 100644
--- a/src/alloy/backend/x64/x64_sequences.cc
+++ b/src/alloy/backend/x64/x64_sequences.cc
@@ -3734,7 +3734,41 @@ EMITTER(VECTOR_SHL_V128, MATCH(I<OPCODE_VECTOR_SHL, V128<>, V128<>, V128<>>)) {
       }
     } else {
       // Fully variable shift.
-      XEASSERTALWAYS();
+      // TODO(benvanik): find a better sequence.
+      Xmm temp = i.dest;
+      if (i.dest == i.src1 || i.dest == i.src2) {
+        temp = e.xmm2;
+      }
+      auto byte_mask = e.GetXmmConstPtr(XMMShiftByteMask);
+      // AABBCCDD|EEFFGGHH|IIJJKKLL|MMNNOOPP
+      //       DD|      HH|      LL|      PP
+      e.vpand(e.xmm0, i.src1, byte_mask);
+      e.vpand(e.xmm1, i.src2, byte_mask);
+      e.vpsllvd(temp, e.xmm0, e.xmm1);
+      //     CC  |    GG  |    KK  |    OO
+      e.vpsrld(e.xmm0, i.src1, 8);
+      e.vpand(e.xmm0, byte_mask);
+      e.vpsrld(e.xmm1, i.src2, 8);
+      e.vpand(e.xmm1, byte_mask);
+      e.vpsllvd(e.xmm0, e.xmm0, e.xmm1);
+      e.vpslld(e.xmm0, 8);
+      e.vpor(temp, e.xmm0);
+      //   BB    |  FF    |  JJ    |  NN
+      e.vpsrld(e.xmm0, i.src1, 16);
+      e.vpand(e.xmm0, byte_mask);
+      e.vpsrld(e.xmm1, i.src2, 16);
+      e.vpand(e.xmm1, byte_mask);
+      e.vpsllvd(e.xmm0, e.xmm0, e.xmm1);
+      e.vpslld(e.xmm0, 16);
+      e.vpor(temp, e.xmm0);
+      // AA      |EE      |II      |MM
+      e.vpsrld(e.xmm0, i.src1, 24);
+      e.vpand(e.xmm0, byte_mask);
+      e.vpsrld(e.xmm1, i.src2, 24);
+      e.vpand(e.xmm1, byte_mask);
+      e.vpsllvd(e.xmm0, e.xmm0, e.xmm1);
+      e.vpslld(e.xmm0, 24);
+      e.vpor(i.dest, temp, e.xmm0);
     }
   }
   static void EmitInt16(X64Emitter& e, const EmitArgType& i) {