ARM: Tweak LoadKeyed.

Avoid corrupting its input.

BUG=none
TEST=none
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/25231005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17042 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 0ea235c..7e03fb8 100644 (file)
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -2226,7 +2226,7 @@ LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
   if (!instr->is_external()) {
     LOperand* obj = NULL;
     if (instr->representation().IsDouble()) {
-      obj = UseTempRegister(instr->elements());
+      obj = UseRegister(instr->elements());
     } else {
       ASSERT(instr->representation().IsSmiOrTagged());
       obj = UseRegisterAtStart(instr->elements());

diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 76c2ca7..ea62488 100644 (file)
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -3295,27 +3295,30 @@ void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
   Register scratch = scratch0();
 
   int element_size_shift = ElementsKindToShiftSize(FAST_DOUBLE_ELEMENTS);
-  int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
-      ? (element_size_shift - kSmiTagSize) : element_size_shift;
-  int constant_key = 0;
+
+  int base_offset =
+      FixedDoubleArray::kHeaderSize - kHeapObjectTag +
+      (instr->additional_index() << element_size_shift);
   if (key_is_constant) {
-    constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
+    int constant_key = ToInteger32(LConstantOperand::cast(instr->key()));
     if (constant_key & 0xF0000000) {
       Abort(kArrayIndexConstantValueTooBig);
     }
-  } else {
-    key = ToRegister(instr->key());
+    base_offset += constant_key << element_size_shift;
   }
+  __ add(scratch, elements, Operand(base_offset));
 
-  int base_offset = (FixedDoubleArray::kHeaderSize - kHeapObjectTag) +
-      ((constant_key + instr->additional_index()) << element_size_shift);
   if (!key_is_constant) {
-    __ add(elements, elements, Operand(key, LSL, shift_size));
+    key = ToRegister(instr->key());
+    int shift_size = (instr->hydrogen()->key()->representation().IsSmi())
+        ? (element_size_shift - kSmiTagSize) : element_size_shift;
+    __ add(scratch, scratch, Operand(key, LSL, shift_size));
   }
-  __ add(elements, elements, Operand(base_offset));
-  __ vldr(result, elements, 0);
+
+  __ vldr(result, scratch, 0);
+
   if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
+    __ ldr(scratch, MemOperand(scratch, sizeof(kHoleNanLower32)));
     __ cmp(scratch, Operand(kHoleNanUpper32));
     DeoptimizeIf(eq, instr->environment());
   }
@@ -3335,7 +3338,7 @@ void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
                                            instr->additional_index());
     store_base = elements;
   } else {
-    Register key = EmitLoadRegister(instr->key(), scratch0());
+    Register key = ToRegister(instr->key());
     // Even though the HLoadKeyed instruction forces the input
     // representation for the key to be an integer, the input gets replaced
     // during bound check elimination with the index argument to the bounds