[wasm] Int64Lowering of I64ShrU and I64ShrS on ia32.

src/ia32/macro-assembler-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 710 matching lines @@
   shld_cl(dst, src);
   shl_cl(src);
   Label done;
   test(ecx, Immediate(0x20));
   j(equal, &done, Label::kNear);
   mov(dst, src);
   xor_(src, src);
   bind(&done);
 }
 
+void MacroAssembler::PairShr(Register dst, Register src, uint8_t shift) {

[titzer, 2016/03/07 19:25:35]

{dst} and {src} are misnamed. They should be {hi} and {lo}, and they are
modified in place.

[ahaas, 2016/03/08 07:58:42]

Done.

+  if (shift >= 32) {
+    mov(src, dst);
+    shr(src, shift - 32);
+    xor_(dst, dst);
+  } else {
+    shrd(dst, src, shift);
+    shr(dst, shift);
+  }
+}
+
+void MacroAssembler::PairShr_cl(Register dst, Register src) {
+  shrd_cl(dst, src);
+  shr_cl(dst);
+  Label done;
+  test(ecx, Immediate(0x20));
+  j(equal, &done, Label::kNear);
+  mov(src, dst);
+  xor_(dst, dst);
+  bind(&done);
+}
+
+void MacroAssembler::PairSar(Register dst, Register src, uint8_t shift) {
+  if (shift >= 32) {
+    mov(src, dst);
+    sar(src, shift - 32);
+    sar(dst, 31);
+  } else {
+    shrd(dst, src, shift);
+    sar(dst, shift);
+  }
+}
+
+void MacroAssembler::PairSar_cl(Register dst, Register src) {
+  shrd_cl(dst, src);
+  sar_cl(dst);
+  Label done;
+  test(ecx, Immediate(0x20));
+  j(equal, &done, Label::kNear);
+  mov(src, dst);
+  sar(dst, 31);
+  bind(&done);
+}
+
 bool MacroAssembler::IsUnsafeImmediate(const Immediate& x) {
   static const int kMaxImmediateBits = 17;
   if (!RelocInfo::IsNone(x.rmode_)) return false;
   return !is_intn(x.x_, kMaxImmediateBits);
 }
 
 
 void MacroAssembler::SafeMove(Register dst, const Immediate& x) {
   if (IsUnsafeImmediate(x) && jit_cookie() != 0) {
     Move(dst, Immediate(x.x_ ^ jit_cookie()));
@@ skipping 2580 matching lines @@
   mov(eax, dividend);
   shr(eax, 31);
   add(edx, eax);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32