Remove support for smi-based keyed accesses on 64bit.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 2378f2b8933b62d3e992431f01413bb577102159..364c3a1824ef671ee44dcd8f984d4be0363da993 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2897,9 +2897,7 @@ void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
     // gets replaced during bound check elimination with the index argument
     // to the bounds check, which can be tagged, so that case must be
     // handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
@@ -2970,9 +2968,7 @@ void LCodeGen::DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr) {
     // representation for the key to be an integer, the input gets replaced
     // during bound check elimination with the index argument to the bounds
     // check, which can be tagged, so that case must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
@@ -3012,9 +3008,7 @@ void LCodeGen::DoLoadKeyedFixedArray(LLoadKeyed* instr) {
     // gets replaced during bound check elimination with the index
     // argument to the bounds check, which can be tagged, so that
     // case must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
@@ -4090,9 +4084,7 @@ void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
     // gets replaced during bound check elimination with the index
     // argument to the bounds check, which can be tagged, so that case
     // must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
@@ -4154,9 +4146,7 @@ void LCodeGen::DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr) {
     // input gets replaced during bound check elimination with the index
     // argument to the bounds check, which can be tagged, so that case
     // must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);
@@ -4197,9 +4187,7 @@ void LCodeGen::DoStoreKeyedFixedArray(LStoreKeyed* instr) {
     // input gets replaced during bound check elimination with the index
     // argument to the bounds check, which can be tagged, so that case
     // must be handled here, too.
-    if (instr->hydrogen()->key()->representation().IsSmi()) {
-      __ SmiToInteger64(key_reg, key_reg);
-    } else if (instr->hydrogen()->IsDehoisted()) {
+    if (instr->hydrogen()->IsDehoisted()) {
       // Sign extend key because it could be a 32 bit negative value
       // and the dehoisted address computation happens in 64 bits
       __ movsxlq(key_reg, key_reg);