Revision: 10541
Author: [email protected]
Date: Fri Jan 27 08:54:22 2012
Log: Some assembler-level optimizations on ARM.
Review URL: https://chromiumcodereview.appspot.com/9223011
http://code.google.com/p/v8/source/detail?r=10541
Modified:
/branches/bleeding_edge/src/arm/code-stubs-arm.cc
/branches/bleeding_edge/src/arm/codegen-arm.cc
/branches/bleeding_edge/src/arm/lithium-codegen-arm.cc
/branches/bleeding_edge/src/arm/macro-assembler-arm.cc
/branches/bleeding_edge/src/arm/macro-assembler-arm.h
=======================================
--- /branches/bleeding_edge/src/arm/code-stubs-arm.cc Fri Jan 27 05:20:01
2012
+++ /branches/bleeding_edge/src/arm/code-stubs-arm.cc Fri Jan 27 08:54:22
2012
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
@@ -122,7 +122,6 @@
__ str(r1, FieldMemOperand(r0, JSFunction::kLiteralsOffset));
__ str(r4, FieldMemOperand(r0, JSFunction::kNextFunctionLinkOffset));
-
// Initialize the code pointer in the function to be the one
// found in the shared function info object.
__ ldr(r3, FieldMemOperand(r3, SharedFunctionInfo::kCodeOffset));
@@ -157,20 +156,18 @@
__ ldr(r3, MemOperand(sp, 0));
// Set up the object header.
- __ LoadRoot(r2, Heap::kFunctionContextMapRootIndex);
- __ str(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
+ __ LoadRoot(r1, Heap::kFunctionContextMapRootIndex);
__ mov(r2, Operand(Smi::FromInt(length)));
__ str(r2, FieldMemOperand(r0, FixedArray::kLengthOffset));
-
- // Set up the fixed slots.
+ __ str(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
+
+ // Set up the fixed slots, copy the global object from the previous
context.
+ __ ldr(r2, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
__ mov(r1, Operand(Smi::FromInt(0)));
__ str(r3, MemOperand(r0, Context::SlotOffset(Context::CLOSURE_INDEX)));
__ str(cp, MemOperand(r0, Context::SlotOffset(Context::PREVIOUS_INDEX)));
__ str(r1, MemOperand(r0,
Context::SlotOffset(Context::EXTENSION_INDEX)));
-
- // Copy the global object from the previous context.
- __ ldr(r1, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
- __ str(r1, MemOperand(r0, Context::SlotOffset(Context::GLOBAL_INDEX)));
+ __ str(r2, MemOperand(r0, Context::SlotOffset(Context::GLOBAL_INDEX)));
// Initialize the rest of the slots to undefined.
__ LoadRoot(r1, Heap::kUndefinedValueRootIndex);
@@ -229,14 +226,12 @@
__ ldr(r3, ContextOperand(r3, Context::CLOSURE_INDEX));
__ bind(&after_sentinel);
- // Set up the fixed slots.
+ // Set up the fixed slots, copy the global object from the previous
context.
+ __ ldr(r2, ContextOperand(cp, Context::GLOBAL_INDEX));
__ str(r3, ContextOperand(r0, Context::CLOSURE_INDEX));
__ str(cp, ContextOperand(r0, Context::PREVIOUS_INDEX));
__ str(r1, ContextOperand(r0, Context::EXTENSION_INDEX));
-
- // Copy the global object from the previous context.
- __ ldr(r1, ContextOperand(cp, Context::GLOBAL_INDEX));
- __ str(r1, ContextOperand(r0, Context::GLOBAL_INDEX));
+ __ str(r2, ContextOperand(r0, Context::GLOBAL_INDEX));
// Initialize the rest of the slots to the hole value.
__ LoadRoot(r1, Heap::kTheHoleValueRootIndex);
@@ -326,8 +321,7 @@
Label double_elements, check_fast_elements;
__ ldr(r0, FieldMemOperand(r3, JSArray::kElementsOffset));
__ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
- __ LoadRoot(ip, Heap::kFixedCOWArrayMapRootIndex);
- __ cmp(r0, ip);
+ __ CompareRoot(r0, Heap::kFixedCOWArrayMapRootIndex);
__ b(ne, &check_fast_elements);
GenerateFastCloneShallowArrayCommon(masm, 0,
COPY_ON_WRITE_ELEMENTS,
&slow_case);
@@ -336,8 +330,7 @@
__ Ret();
__ bind(&check_fast_elements);
- __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
- __ cmp(r0, ip);
+ __ CompareRoot(r0, Heap::kFixedArrayMapRootIndex);
__ b(ne, &double_elements);
GenerateFastCloneShallowArrayCommon(masm, length_,
CLONE_ELEMENTS, &slow_case);
@@ -590,7 +583,9 @@
Label is_smi, done;
- __ JumpIfSmi(object, &is_smi);
+ // Smi-check
+ __ UntagAndJumpIfSmi(scratch1, object, &is_smi);
+ // Heap number check
__ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_number);
// Handle loading a double from a heap number.
@@ -612,7 +607,6 @@
if (CpuFeatures::IsSupported(VFP3)) {
CpuFeatures::Scope scope(VFP3);
// Convert smi to double using VFP instructions.
- __ SmiUntag(scratch1, object);
__ vmov(dst.high(), scratch1);
__ vcvt_f64_s32(dst, dst.high());
if (destination == kCoreRegisters) {
@@ -647,11 +641,10 @@
Heap::kHeapNumberMapRootIndex,
"HeapNumberMap register clobbered.");
}
- Label is_smi;
Label done;
Label not_in_int32_range;
- __ JumpIfSmi(object, &is_smi);
+ __ UntagAndJumpIfSmi(dst, object, &done);
__ ldr(scratch1, FieldMemOperand(object, HeapNumber::kMapOffset));
__ cmp(scratch1, heap_number_map);
__ b(ne, not_number);
@@ -671,10 +664,6 @@
scratch1,
scratch2,
scratch3);
- __ jmp(&done);
-
- __ bind(&is_smi);
- __ SmiUntag(dst, object);
__ bind(&done);
}
@@ -847,10 +836,7 @@
Label done;
- // Untag the object into the destination register.
- __ SmiUntag(dst, object);
- // Just return if the object is a smi.
- __ JumpIfSmi(object, &done);
+ __ UntagAndJumpIfSmi(dst, object, &done);
if (FLAG_debug_code) {
__ AbortIfNotRootValue(heap_number_map,
@@ -3310,8 +3296,7 @@
// Check if cache matches: Double value is stored in uint32_t[2] array.
__ ldm(ia, cache_entry, r4.bit() | r5.bit() | r6.bit());
__ cmp(r2, r4);
- __ b(ne, &calculate);
- __ cmp(r3, r5);
+ __ cmp(r3, r5, eq);
__ b(ne, &calculate);
// Cache hit. Load result, cleanup and return.
Counters* counters = masm->isolate()->counters();
@@ -3468,7 +3453,7 @@
const Register scratch = r9;
const Register scratch2 = r7;
- Label call_runtime, done, exponent_not_smi, int_exponent;
+ Label call_runtime, done, int_exponent;
if (exponent_type_ == ON_STACK) {
Label base_is_smi, unpack_exponent;
// The exponent and base are supplied as arguments on the stack.
@@ -3479,7 +3464,7 @@
__ LoadRoot(heapnumbermap, Heap::kHeapNumberMapRootIndex);
- __ JumpIfSmi(base, &base_is_smi);
+ __ UntagAndJumpIfSmi(scratch, base, &base_is_smi);
__ ldr(scratch, FieldMemOperand(base, JSObject::kMapOffset));
__ cmp(scratch, heapnumbermap);
__ b(ne, &call_runtime);
@@ -3488,16 +3473,12 @@
__ jmp(&unpack_exponent);
__ bind(&base_is_smi);
- __ SmiUntag(base);
- __ vmov(single_scratch, base);
+ __ vmov(single_scratch, scratch);
__ vcvt_f64_s32(double_base, single_scratch);
__ bind(&unpack_exponent);
- __ JumpIfNotSmi(exponent, &exponent_not_smi);
- __ SmiUntag(exponent);
- __ jmp(&int_exponent);
-
- __ bind(&exponent_not_smi);
+ __ UntagAndJumpIfSmi(scratch, exponent, &int_exponent);
+
__ ldr(scratch, FieldMemOperand(exponent, JSObject::kMapOffset));
__ cmp(scratch, heapnumbermap);
__ b(ne, &call_runtime);
@@ -3505,11 +3486,8 @@
FieldMemOperand(exponent, HeapNumber::kValueOffset));
} else if (exponent_type_ == TAGGED) {
// Base is already in double_base.
- __ JumpIfNotSmi(exponent, &exponent_not_smi);
- __ SmiUntag(exponent);
- __ jmp(&int_exponent);
-
- __ bind(&exponent_not_smi);
+ __ UntagAndJumpIfSmi(scratch, exponent, &int_exponent);
+
__ vldr(double_exponent,
FieldMemOperand(exponent, HeapNumber::kValueOffset));
}
@@ -3582,13 +3560,19 @@
__ bind(&int_exponent_convert);
__ vcvt_u32_f64(single_scratch, double_exponent);
- __ vmov(exponent, single_scratch);
+ __ vmov(scratch, single_scratch);
}
// Calculate power with integer exponent.
__ bind(&int_exponent);
- __ mov(scratch, exponent); // Back up exponent.
+ // Get two copies of exponent in the registers scratch and exponent.
+ if (exponent_type_ == INTEGER) {
+ __ mov(scratch, exponent);
+ } else {
+ // Exponent has previously been stored into scratch as untagged
integer.
+ __ mov(exponent, scratch);
+ }
__ vmov(double_scratch, double_base); // Back up base.
__ vmov(double_result, 1.0);
@@ -4098,11 +4082,9 @@
// real lookup and update the call site cache.
if (!HasCallSiteInlineCheck()) {
Label miss;
- __ LoadRoot(ip, Heap::kInstanceofCacheFunctionRootIndex);
- __ cmp(function, ip);
+ __ CompareRoot(function, Heap::kInstanceofCacheFunctionRootIndex);
__ b(ne, &miss);
- __ LoadRoot(ip, Heap::kInstanceofCacheMapRootIndex);
- __ cmp(map, ip);
+ __ CompareRoot(map, Heap::kInstanceofCacheMapRootIndex);
__ b(ne, &miss);
__ LoadRoot(r0, Heap::kInstanceofCacheAnswerRootIndex);
__ Ret(HasArgsInRegisters() ? 0 : 2);
@@ -4727,8 +4709,7 @@
__ ldr(last_match_info_elements,
FieldMemOperand(r0, JSArray::kElementsOffset));
__ ldr(r0, FieldMemOperand(last_match_info_elements,
HeapObject::kMapOffset));
- __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
- __ cmp(r0, ip);
+ __ CompareRoot(r0, Heap::kFixedArrayMapRootIndex);
__ b(ne, &runtime);
// Check that the last match info has space for the capture registers
and the
// additional information.
@@ -5082,11 +5063,11 @@
// Set input, index and length fields from arguments.
__ ldr(r1, MemOperand(sp, kPointerSize * 0));
+ __ ldr(r2, MemOperand(sp, kPointerSize * 1));
+ __ ldr(r6, MemOperand(sp, kPointerSize * 2));
__ str(r1, FieldMemOperand(r0, JSRegExpResult::kInputOffset));
- __ ldr(r1, MemOperand(sp, kPointerSize * 1));
- __ str(r1, FieldMemOperand(r0, JSRegExpResult::kIndexOffset));
- __ ldr(r1, MemOperand(sp, kPointerSize * 2));
- __ str(r1, FieldMemOperand(r0, JSArray::kLengthOffset));
+ __ str(r2, FieldMemOperand(r0, JSRegExpResult::kIndexOffset));
+ __ str(r6, FieldMemOperand(r0, JSArray::kLengthOffset));
// Fill out the elements FixedArray.
// r0: JSArray, tagged.
@@ -5436,8 +5417,7 @@
STATIC_ASSERT(kSmiTag == 0);
__ add(result_, result_, Operand(code_, LSL, kPointerSizeLog2 -
kSmiTagSize));
__ ldr(result_, FieldMemOperand(result_, FixedArray::kHeaderSize));
- __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
- __ cmp(result_, Operand(ip));
+ __ CompareRoot(result_, Heap::kUndefinedValueRootIndex);
__ b(eq, &slow_case_);
__ bind(&exit_);
}
@@ -5865,10 +5845,11 @@
__ mov(r3, Operand(r3, ASR, 1), SetCC, cc);
// If either to or from had the smi tag bit set, then carry is set now.
__ b(cs, &runtime); // Either "from" or "to" is not a smi.
- __ b(mi, &runtime); // From is negative.
-
+ // We want to bailout to runtime here if From is negative. In that
case, the
+ // next instruction is not executed and we fall through to bailing out to
+ // runtime. pl is the opposite of mi.
// Both r2 and r3 are untagged integers.
- __ sub(r2, r2, Operand(r3), SetCC);
+ __ sub(r2, r2, Operand(r3), SetCC, pl);
__ b(mi, &runtime); // Fail if from > to.
// Make sure first argument is a string.
@@ -5941,9 +5922,9 @@
__ bind(&sliced_string);
// Sliced string. Fetch parent and correct start index by offset.
- __ ldr(r5, FieldMemOperand(r0, SlicedString::kOffsetOffset));
- __ add(r3, r3, Operand(r5, ASR, 1));
+ __ ldr(r4, FieldMemOperand(r0, SlicedString::kOffsetOffset));
__ ldr(r5, FieldMemOperand(r0, SlicedString::kParentOffset));
+ __ add(r3, r3, Operand(r4, ASR, 1)); // Add offset to index.
// Update instance type.
__ ldr(r1, FieldMemOperand(r5, HeapObject::kMapOffset));
__ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
=======================================
--- /branches/bleeding_edge/src/arm/codegen-arm.cc Thu Nov 24 03:07:39 2011
+++ /branches/bleeding_edge/src/arm/codegen-arm.cc Fri Jan 27 08:54:22 2012
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
@@ -104,10 +104,10 @@
__ add(lr, lr, Operand(r5, LSL, 2));
__ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
// r6: destination FixedDoubleArray, not tagged as heap object
+ // Set destination FixedDoubleArray's length and map.
__ LoadRoot(r9, Heap::kFixedDoubleArrayMapRootIndex);
- __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
- // Set destination FixedDoubleArray's length.
__ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
+ __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
// Update receiver's map.
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
@@ -155,10 +155,9 @@
__ bind(&loop);
__ ldr(r9, MemOperand(r3, 4, PostIndex));
// r9: current element
- __ JumpIfNotSmi(r9, &convert_hole);
+ __ UntagAndJumpIfNotSmi(r9, r9, &convert_hole);
// Normal smi, convert to double and store.
- __ SmiUntag(r9);
if (vfp3_supported) {
CpuFeatures::Scope scope(VFP3);
__ vmov(s0, r9);
@@ -181,6 +180,9 @@
// Hole found, store the-hole NaN.
__ bind(&convert_hole);
if (FLAG_debug_code) {
+ // Restore a "smi-untagged" heap object.
+ __ SmiTag(r9);
+ __ orr(r9, r9, Operand(1));
__ CompareRoot(r9, Heap::kTheHoleValueRootIndex);
__ Assert(eq, "object found in smi-only array");
}
@@ -208,9 +210,8 @@
Label entry, loop, convert_hole, gc_required;
__ push(lr);
- __ Push(r3, r2, r1, r0);
-
__ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
+ __ Push(r3, r2, r1, r0);
__ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
// r4: source FixedDoubleArray
// r5: number of elements (smi-tagged)
@@ -220,10 +221,10 @@
__ add(r0, r0, Operand(r5, LSL, 1));
__ AllocateInNewSpace(r0, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
// r6: destination FixedArray, not tagged as heap object
+ // Set destination FixedDoubleArray's length and map.
__ LoadRoot(r9, Heap::kFixedArrayMapRootIndex);
- __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
- // Set destination FixedDoubleArray's length.
__ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
+ __ str(r9, MemOperand(r6, HeapObject::kMapOffset));
// Prepare for conversion loop.
__ add(r4, r4, Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag +
4));
@@ -325,8 +326,8 @@
// Handle slices.
Label indirect_string_loaded;
__ ldr(result, FieldMemOperand(string, SlicedString::kOffsetOffset));
- __ add(index, index, Operand(result, ASR, kSmiTagSize));
__ ldr(string, FieldMemOperand(string, SlicedString::kParentOffset));
+ __ add(index, index, Operand(result, ASR, kSmiTagSize));
__ jmp(&indirect_string_loaded);
// Handle cons strings.
@@ -336,8 +337,7 @@
// the string.
__ bind(&cons_string);
__ ldr(result, FieldMemOperand(string, ConsString::kSecondOffset));
- __ LoadRoot(ip, Heap::kEmptyStringRootIndex);
- __ cmp(result, ip);
+ __ CompareRoot(result, Heap::kEmptyStringRootIndex);
__ b(ne, call_runtime);
// Get the first of the two strings and load its instance type.
__ ldr(string, FieldMemOperand(string, ConsString::kFirstOffset));
=======================================
--- /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Fri Jan 27
06:55:20 2012
+++ /branches/bleeding_edge/src/arm/lithium-codegen-arm.cc Fri Jan 27
08:54:22 2012
@@ -3929,7 +3929,7 @@
Label load_smi, heap_number, done;
// Smi check.
- __ JumpIfSmi(input_reg, &load_smi);
+ __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
// Heap number map check.
__ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
@@ -3968,7 +3968,7 @@
// Smi to double register conversion
__ bind(&load_smi);
- __ SmiUntag(scratch, input_reg); // Untag smi before converting to
float.
+ // scratch: untagged value of input_reg
__ vmov(flt_scratch, scratch);
__ vcvt_f64_s32(result_reg, flt_scratch);
__ bind(&done);
@@ -4256,7 +4256,7 @@
Label is_smi, done, heap_number;
// Both smi and heap number cases are handled.
- __ JumpIfSmi(input_reg, &is_smi);
+ __ UntagAndJumpIfSmi(result_reg, input_reg, &is_smi);
// Check for heap number
__ ldr(scratch, FieldMemOperand(input_reg, HeapObject::kMapOffset));
@@ -4279,7 +4279,6 @@
// smi
__ bind(&is_smi);
- __ SmiUntag(result_reg, input_reg);
__ ClampUint8(result_reg, result_reg);
__ bind(&done);
=======================================
--- /branches/bleeding_edge/src/arm/macro-assembler-arm.cc Thu Jan 26
13:47:57 2012
+++ /branches/bleeding_edge/src/arm/macro-assembler-arm.cc Fri Jan 27
08:54:22 2012
@@ -2963,6 +2963,22 @@
tst(reg2, Operand(kSmiTagMask), eq);
b(ne, on_not_both_smi);
}
+
+
+void MacroAssembler::UntagAndJumpIfSmi(
+ Register dst, Register src, Label* smi_case) {
+ STATIC_ASSERT(kSmiTag == 0);
+ mov(dst, Operand(src, ASR, kSmiTagSize), SetCC);
+ b(cc, smi_case); // Shifter carry is not set for a smi.
+}
+
+
+void MacroAssembler::UntagAndJumpIfNotSmi(
+ Register dst, Register src, Label* non_smi_case) {
+ STATIC_ASSERT(kSmiTag == 0);
+ mov(dst, Operand(src, ASR, kSmiTagSize), SetCC);
+ b(cs, non_smi_case); // Shifter carry is set for a non-smi.
+}
void MacroAssembler::JumpIfEitherSmi(Register reg1,
=======================================
--- /branches/bleeding_edge/src/arm/macro-assembler-arm.h Thu Jan 26
13:47:57 2012
+++ /branches/bleeding_edge/src/arm/macro-assembler-arm.h Fri Jan 27
08:54:22 2012
@@ -1148,6 +1148,14 @@
void SmiUntag(Register dst, Register src, SBit s = LeaveCC) {
mov(dst, Operand(src, ASR, kSmiTagSize), s);
}
+
+ // Untag the source value into destination and jump if source is a smi.
+ // Souce and destination can be the same register.
+ void UntagAndJumpIfSmi(Register dst, Register src, Label* smi_case);
+
+ // Untag the source value into destination and jump if source is not a
smi.
+ // Souce and destination can be the same register.
+ void UntagAndJumpIfNotSmi(Register dst, Register src, Label*
non_smi_case);
// Jump the register contains a smi.
inline void JumpIfSmi(Register value, Label* smi_label) {
--
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