From: jkummerow@chromium.org Date: Tue, 11 Jun 2013 10:47:44 +0000 (+0000) Subject: Increase sanity of integer division handling on ARM X-Git-Tag: upstream/4.7.83~13914 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=57632e208a17e55c437bdd62da6c85cb0b863df8;p=platform%2Fupstream%2Fv8.git Increase sanity of integer division handling on ARM - In the INT32 BinaryOpStub, fix type feedback collection for DIV, bringing it in line with other platforms. - In Lithium codegen, emit proper inlined code, don't call the stub. - Drive-by fix: assert appropriate CpuFeaturesScope for SDIV. R=ulan@chromium.org Review URL: https://codereview.chromium.org/16082008 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15057 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- diff --git a/src/arm/assembler-arm.cc b/src/arm/assembler-arm.cc index 66c3dbf03..c6ea6006f 100644 --- a/src/arm/assembler-arm.cc +++ b/src/arm/assembler-arm.cc @@ -1368,6 +1368,7 @@ void Assembler::mls(Register dst, Register src1, Register src2, Register srcA, void Assembler::sdiv(Register dst, Register src1, Register src2, Condition cond) { ASSERT(!dst.is(pc) && !src1.is(pc) && !src2.is(pc)); + ASSERT(IsEnabled(SUDIV)); emit(cond | B26 | B25| B24 | B20 | dst.code()*B16 | 0xf * B12 | src2.code()*B8 | B4 | src1.code()); } diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc index 3fbe0c5ea..b26bf7ede 100644 --- a/src/arm/code-stubs-arm.cc +++ b/src/arm/code-stubs-arm.cc @@ -1707,6 +1707,7 @@ void BinaryOpStub_GenerateSmiSmiOperation(MacroAssembler* masm, __ Ret(); if (CpuFeatures::IsSupported(SUDIV)) { + CpuFeatureScope scope(masm, SUDIV); Label result_not_zero; __ bind(&div_with_sdiv); @@ -1763,6 +1764,7 @@ void BinaryOpStub_GenerateSmiSmiOperation(MacroAssembler* masm, __ Ret(); if (CpuFeatures::IsSupported(SUDIV)) { + CpuFeatureScope scope(masm, SUDIV); __ bind(&modulo_with_sdiv); __ mov(scratch2, right); // Perform modulus with sdiv and mls. @@ -2208,42 +2210,25 @@ void BinaryOpStub::GenerateInt32Stub(MacroAssembler* masm) { UNREACHABLE(); } - if (op_ != Token::DIV) { - // These operations produce an integer result. - // Try to return a smi if we can. - // Otherwise return a heap number if allowed, or jump to type - // transition. - - if (result_type_ <= BinaryOpIC::INT32) { - __ TryDoubleToInt32Exact(scratch1, d5, d8); - // If the ne condition is set, result does - // not fit in a 32-bit integer. - __ b(ne, &transition); - } else { - __ vcvt_s32_f64(s8, d5); - __ vmov(scratch1, s8); - } - - // Check if the result fits in a smi. - __ add(scratch2, scratch1, Operand(0x40000000), SetCC); - // If not try to return a heap number. - __ b(mi, &return_heap_number); - // Check for minus zero. Return heap number for minus zero if - // double results are allowed; otherwise transition. + if (result_type_ <= BinaryOpIC::INT32) { + __ TryDoubleToInt32Exact(scratch1, d5, d8); + // If the ne condition is set, result does + // not fit in a 32-bit integer. + __ b(ne, &transition); + // Try to tag the result as a Smi, return heap number on overflow. + __ SmiTag(scratch1, SetCC); + __ b(vs, &return_heap_number); + // Check for minus zero, transition in that case (because we need + // to return a heap number). Label not_zero; - __ cmp(scratch1, Operand::Zero()); + ASSERT(kSmiTag == 0); __ b(ne, ¬_zero); __ vmov(scratch2, d5.high()); __ tst(scratch2, Operand(HeapNumber::kSignMask)); - __ b(ne, result_type_ <= BinaryOpIC::INT32 ? &transition - : &return_heap_number); + __ b(ne, &transition); __ bind(¬_zero); - - // Tag the result and return. - __ SmiTag(r0, scratch1); + __ mov(r0, scratch1); __ Ret(); - } else { - // DIV just falls through to allocating a heap number. } __ bind(&return_heap_number); diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc index d9f9053af..fbb9c6ef8 100644 --- a/src/arm/lithium-arm.cc +++ b/src/arm/lithium-arm.cc @@ -1345,18 +1345,14 @@ LInstruction* LChunkBuilder::DoDiv(HDiv* instr) { ASSERT(!instr->CheckFlag(HValue::kCanBeDivByZero)); LOperand* value = UseRegisterAtStart(instr->left()); LDivI* div = - new(zone()) LDivI(value, UseOrConstant(instr->right())); + new(zone()) LDivI(value, UseOrConstant(instr->right()), NULL); return AssignEnvironment(DefineSameAsFirst(div)); } - // TODO(1042) The fixed register allocation - // is needed because we call TypeRecordingBinaryOpStub from - // the generated code, which requires registers r0 - // and r1 to be used. We should remove that - // when we provide a native implementation. - LOperand* dividend = UseFixed(instr->left(), r0); - LOperand* divisor = UseFixed(instr->right(), r1); - return AssignEnvironment(AssignPointerMap( - DefineFixed(new(zone()) LDivI(dividend, divisor), r0))); + LOperand* dividend = UseRegister(instr->left()); + LOperand* divisor = UseRegister(instr->right()); + LOperand* temp = CpuFeatures::IsSupported(SUDIV) ? NULL : FixedTemp(d4); + LDivI* div = new(zone()) LDivI(dividend, divisor, temp); + return AssignEnvironment(DefineAsRegister(div)); } else { return DoArithmeticT(Token::DIV, instr); } diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h index 096427542..ccfd0dbec 100644 --- a/src/arm/lithium-arm.h +++ b/src/arm/lithium-arm.h @@ -597,15 +597,17 @@ class LModI: public LTemplateInstruction<1, 2, 2> { }; -class LDivI: public LTemplateInstruction<1, 2, 0> { +class LDivI: public LTemplateInstruction<1, 2, 1> { public: - LDivI(LOperand* left, LOperand* right) { + LDivI(LOperand* left, LOperand* right, LOperand* temp) { inputs_[0] = left; inputs_[1] = right; + temps_[0] = temp; } LOperand* left() { return inputs_[0]; } LOperand* right() { return inputs_[1]; } + LOperand* temp() { return temps_[0]; } DECLARE_CONCRETE_INSTRUCTION(DivI, "div-i") DECLARE_HYDROGEN_ACCESSOR(Div) diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc index c42e6517e..ae134f77e 100644 --- a/src/arm/lithium-codegen-arm.cc +++ b/src/arm/lithium-codegen-arm.cc @@ -1417,21 +1417,6 @@ void LCodeGen::EmitSignedIntegerDivisionByConstant( void LCodeGen::DoDivI(LDivI* instr) { - class DeferredDivI: public LDeferredCode { - public: - DeferredDivI(LCodeGen* codegen, LDivI* instr) - : LDeferredCode(codegen), instr_(instr) { } - virtual void Generate() { - codegen()->DoDeferredBinaryOpStub(instr_->pointer_map(), - instr_->left(), - instr_->right(), - Token::DIV); - } - virtual LInstruction* instr() { return instr_; } - private: - LDivI* instr_; - }; - if (instr->hydrogen()->HasPowerOf2Divisor()) { Register dividend = ToRegister(instr->left()); int32_t divisor = @@ -1498,40 +1483,32 @@ void LCodeGen::DoDivI(LDivI* instr) { __ bind(&left_not_min_int); } - Label done, deoptimize; - // Test for a few common cases first. - __ cmp(right, Operand(1)); - __ mov(result, left, LeaveCC, eq); - __ b(eq, &done); - - __ cmp(right, Operand(2)); - __ tst(left, Operand(1), eq); - __ mov(result, Operand(left, ASR, 1), LeaveCC, eq); - __ b(eq, &done); - - __ cmp(right, Operand(4)); - __ tst(left, Operand(3), eq); - __ mov(result, Operand(left, ASR, 2), LeaveCC, eq); - __ b(eq, &done); - - // Call the stub. The numbers in r0 and r1 have - // to be tagged to Smis. If that is not possible, deoptimize. - DeferredDivI* deferred = new(zone()) DeferredDivI(this, instr); - - __ TrySmiTag(left, &deoptimize); - __ TrySmiTag(right, &deoptimize); - - __ b(al, deferred->entry()); - __ bind(deferred->exit()); - - // If the result in r0 is a Smi, untag it, else deoptimize. - __ JumpIfNotSmi(result, &deoptimize); - __ SmiUntag(result); - __ b(&done); + if (CpuFeatures::IsSupported(SUDIV)) { + CpuFeatureScope scope(masm(), SUDIV); + __ sdiv(result, left, right); - __ bind(&deoptimize); - DeoptimizeIf(al, instr->environment()); - __ bind(&done); + // Compute remainder and deopt if it's not zero. + const Register remainder = scratch0(); + __ mls(remainder, result, right, left); + __ cmp(remainder, Operand::Zero()); + DeoptimizeIf(ne, instr->environment()); + } else { + const DoubleRegister vleft = ToDoubleRegister(instr->temp()); + const DoubleRegister vright = double_scratch0(); + __ vmov(vleft.low(), left); + __ vmov(vright.low(), right); + __ vcvt_f64_s32(vleft, vleft.low()); + __ vcvt_f64_s32(vright, vright.low()); + __ vdiv(vleft, vleft, vright); // vleft now contains the result. + + // Convert back to integer32; deopt if exact conversion is not possible. + // Use vright as scratch register. + __ vcvt_s32_f64(vright.low(), vleft); + __ vmov(result, vright.low()); + __ vcvt_f64_s32(vright, vright.low()); + __ VFPCompareAndSetFlags(vleft, vright); + DeoptimizeIf(ne, instr->environment()); + } } @@ -1630,38 +1607,6 @@ void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) { } -void LCodeGen::DoDeferredBinaryOpStub(LPointerMap* pointer_map, - LOperand* left_argument, - LOperand* right_argument, - Token::Value op) { - Register left = ToRegister(left_argument); - Register right = ToRegister(right_argument); - - PushSafepointRegistersScope scope(this, Safepoint::kWithRegistersAndDoubles); - // Move left to r1 and right to r0 for the stub call. - if (left.is(r1)) { - __ Move(r0, right); - } else if (left.is(r0) && right.is(r1)) { - __ Swap(r0, r1, r2); - } else if (left.is(r0)) { - ASSERT(!right.is(r1)); - __ mov(r1, r0); - __ mov(r0, right); - } else { - ASSERT(!left.is(r0) && !right.is(r0)); - __ mov(r0, right); - __ mov(r1, left); - } - BinaryOpStub stub(op, OVERWRITE_LEFT); - __ CallStub(&stub); - RecordSafepointWithRegistersAndDoubles(pointer_map, - 0, - Safepoint::kNoLazyDeopt); - // Overwrite the stored value of r0 with the result of the stub. - __ StoreToSafepointRegistersAndDoublesSlot(r0, r0); -} - - void LCodeGen::DoMulI(LMulI* instr) { Register scratch = scratch0(); Register result = ToRegister(instr->result()); diff --git a/src/arm/lithium-codegen-arm.h b/src/arm/lithium-codegen-arm.h index a22d19243..cecf152ee 100644 --- a/src/arm/lithium-codegen-arm.h +++ b/src/arm/lithium-codegen-arm.h @@ -138,10 +138,6 @@ class LCodeGen BASE_EMBEDDED { void FinishCode(Handle code); // Deferred code support. - void DoDeferredBinaryOpStub(LPointerMap* pointer_map, - LOperand* left_argument, - LOperand* right_argument, - Token::Value op); void DoDeferredNumberTagD(LNumberTagD* instr); enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 }; diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc index 073f7a1c7..2033ea422 100644 --- a/src/hydrogen-instructions.cc +++ b/src/hydrogen-instructions.cc @@ -1513,6 +1513,11 @@ HValue* HUnaryMathOperation::Canonicalize() { // If the input is integer32 then we replace the floor instruction // with its input. This happens before the representation changes are // introduced. + + // TODO(2205): The above comment is lying. All of this happens + // *after* representation changes are introduced. We should check + // for value->IsChange() and react accordingly if yes. + if (value()->representation().IsInteger32()) return value(); #if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_IA32) || \ diff --git a/src/ia32/assembler-ia32.cc b/src/ia32/assembler-ia32.cc index 7b32f1b1d..c0b2abd51 100644 --- a/src/ia32/assembler-ia32.cc +++ b/src/ia32/assembler-ia32.cc @@ -2351,7 +2351,7 @@ void Assembler::movd(const Operand& dst, XMMRegister src) { void Assembler::extractps(Register dst, XMMRegister src, byte imm8) { - ASSERT(CpuFeatures::IsSupported(SSE4_1)); + ASSERT(IsEnabled(SSE4_1)); ASSERT(is_uint8(imm8)); EnsureSpace ensure_space(this); EMIT(0x66);