Bug 1438727: [Part 15] Implement flexible shift macroassembler helpers r=tcampbell

--HG--
extra : rebase_source : 7c9f3cc7651d2ce8067df328705ff0d219d2c9eb

js/src/jit/MacroAssembler.h

@@ -913,6 +913,11 @@ class MacroAssembler : public MacroAssemblerSpecific
     inline void rshift32(Register shift, Register srcDest) PER_SHARED_ARCH;
     inline void rshift32Arithmetic(Register shift, Register srcDest) PER_SHARED_ARCH;
 
+    // These variants may use the stack, but do not have the above constraint.
+    inline void flexibleLshift32(Register shift, Register srcDest) PER_SHARED_ARCH;
+    inline void flexibleRshift32(Register shift, Register srcDest) PER_SHARED_ARCH;
+    inline void flexibleRshift32Arithmetic(Register shift, Register srcDest) PER_SHARED_ARCH;
+
     inline void lshift64(Register shift, Register64 srcDest) PER_ARCH;
     inline void rshift64(Register shift, Register64 srcDest) PER_ARCH;
     inline void rshift64Arithmetic(Register shift, Register64 srcDest) PER_ARCH;

js/src/jit/arm/MacroAssembler-arm-inl.h

@@ -756,6 +756,12 @@ MacroAssembler::lshift32(Register src, Register dest)
     ma_lsl(src, dest, dest);
 }
 
+void
+MacroAssembler::flexibleLshift32(Register src, Register dest)
+{
+    lshift32(src,dest);
+}
+
 void
 MacroAssembler::lshift32(Imm32 imm, Register dest)
 {
@@ -777,6 +783,12 @@ MacroAssembler::rshift32(Register src, Register dest)
     ma_lsr(src, dest, dest);
 }
 
+void
+MacroAssembler::flexibleRshift32(Register src, Register dest)
+{
+    rshift32(src,dest);
+}
+
 void
 MacroAssembler::rshift32(Imm32 imm, Register dest)
 {
@@ -852,6 +864,12 @@ MacroAssembler::rshift32Arithmetic(Imm32 imm, Register dest)
     rshiftPtrArithmetic(imm, dest);
 }
 
+void
+MacroAssembler::flexibleRshift32Arithmetic(Register src, Register dest)
+{
+    rshift32Arithmetic(src,dest);
+}
+
 void
 MacroAssembler::rshift64(Imm32 imm, Register64 dest)
 {

js/src/jit/arm64/MacroAssembler-arm64-inl.h

@@ -691,6 +691,12 @@ MacroAssembler::lshift32(Register shift, Register dest)
     Lsl(ARMRegister(dest, 32), ARMRegister(dest, 32), ARMRegister(shift, 32));
 }
 
+void
+MacroAssembler::flexibleLshift32(Register src, Register dest)
+{
+    lshift32(src,dest);
+}
+
 void
 MacroAssembler::lshift32(Imm32 imm, Register dest)
 {
@@ -718,6 +724,12 @@ MacroAssembler::rshift32(Register shift, Register dest)
     Lsr(ARMRegister(dest, 32), ARMRegister(dest, 32), ARMRegister(shift, 32));
 }
 
+void
+MacroAssembler::flexibleRshift32(Register src, Register dest)
+{
+    rshift32(src,dest);
+}
+
 void
 MacroAssembler::rshift32(Imm32 imm, Register dest)
 {
@@ -745,6 +757,12 @@ MacroAssembler::rshift32Arithmetic(Imm32 imm, Register dest)
     Asr(ARMRegister(dest, 32), ARMRegister(dest, 32), imm.value);
 }
 
+void
+MacroAssembler::flexibleRshift32Arithmetic(Register src, Register dest)
+{
+    rshift32Arithmetic(src,dest);
+}
+
 void
 MacroAssembler::rshift64(Imm32 imm, Register64 dest)
 {

js/src/jit/mips-shared/MacroAssembler-mips-shared-inl.h

@@ -335,6 +335,12 @@ MacroAssembler::lshift32(Register src, Register dest)
     ma_sll(dest, dest, src);
 }
 
+void
+MacroAssembler::flexibleLshift32(Register src, Register dest)
+{
+    lshift32(src,dest);
+}
+
 void
 MacroAssembler::lshift32(Imm32 imm, Register dest)
 {
@@ -347,6 +353,12 @@ MacroAssembler::rshift32(Register src, Register dest)
     ma_srl(dest, dest, src);
 }
 
+void
+MacroAssembler::flexibleRshift32(Register src, Register dest)
+{
+    rshift32(src,dest);
+}
+
 void
 MacroAssembler::rshift32(Imm32 imm, Register dest)
 {
@@ -359,6 +371,12 @@ MacroAssembler::rshift32Arithmetic(Register src, Register dest)
     ma_sra(dest, dest, src);
 }
 
+void
+MacroAssembler::flexibleRshift32Arithmetic(Register src, Register dest)
+{
+    rshift32Arithmetic(src,dest);
+}
+
 void
 MacroAssembler::rshift32Arithmetic(Imm32 imm, Register dest)
 {

js/src/jit/x86-shared/MacroAssembler-x86-shared-inl.h

@@ -420,6 +420,34 @@ MacroAssembler::lshift32(Register shift, Register srcDest)
     shll_cl(srcDest);
 }
 
+inline void
+FlexibleShift32(MacroAssembler& masm, Register shift, Register dest, bool left, bool arithmetic = false)
+{
+    if (shift != ecx) {
+        if (dest != ecx)
+            masm.push(ecx);
+        masm.mov(shift, ecx);
+    }
+
+    if (left) {
+        masm.lshift32(ecx, dest);
+    } else {
+        if (arithmetic)
+            masm.rshift32Arithmetic(ecx, dest);
+        else
+            masm.rshift32(ecx, dest);
+    }
+
+    if (shift != ecx && dest != ecx)
+        masm.pop(ecx);
+}
+
+void
+MacroAssembler::flexibleLshift32(Register shift, Register srcDest)
+{
+    FlexibleShift32(*this, shift, srcDest, true);
+}
+
 void
 MacroAssembler::rshift32(Register shift, Register srcDest)
 {
@@ -427,6 +455,12 @@ MacroAssembler::rshift32(Register shift, Register srcDest)
     shrl_cl(srcDest);
 }
 
+void
+MacroAssembler::flexibleRshift32(Register shift, Register srcDest)
+{
+    FlexibleShift32(*this, shift, srcDest, false, false);
+}
+
 void
 MacroAssembler::rshift32Arithmetic(Register shift, Register srcDest)
 {
@@ -434,6 +468,12 @@ MacroAssembler::rshift32Arithmetic(Register shift, Register srcDest)
     sarl_cl(srcDest);
 }
 
+void
+MacroAssembler::flexibleRshift32Arithmetic(Register shift, Register srcDest)
+{
+    FlexibleShift32(*this, shift, srcDest, false, true);
+}
+
 void
 MacroAssembler::lshift32(Imm32 shift, Register srcDest)
 {