static void stringCharLoad(SpecializedThunkJIT& jit)
{
// load string
jit.loadJSStringArgument(SpecializedThunkJIT::ThisArgument, SpecializedThunkJIT::regT0);
// Load string length to regT2, and start the process of loading the data pointer into regT0
jit.load32(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringLengthOffset()), SpecializedThunkJIT::regT2);
jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringValueOffset()), SpecializedThunkJIT::regT0);
jit.appendFailure(jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0));
jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::stringImplDataOffset()), SpecializedThunkJIT::regT0);
// load index
jit.loadInt32Argument(0, SpecializedThunkJIT::regT1); // regT1 contains the index
// Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large
jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, SpecializedThunkJIT::regT1, SpecializedThunkJIT::regT2));
// Load the character
jit.load16(MacroAssembler::BaseIndex(SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1, MacroAssembler::TimesTwo, 0), SpecializedThunkJIT::regT0);
}
static void charToString(SpecializedThunkJIT& jit, JSGlobalData* globalData, MacroAssembler::RegisterID src, MacroAssembler::RegisterID dst, MacroAssembler::RegisterID scratch)
{
jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, src, MacroAssembler::TrustedImm32(0x100)));
jit.move(MacroAssembler::TrustedImmPtr(globalData->smallStrings.singleCharacterStrings()), scratch);
jit.loadPtr(MacroAssembler::BaseIndex(scratch, src, MacroAssembler::ScalePtr, 0), dst);
jit.appendFailure(jit.branchTestPtr(MacroAssembler::Zero, dst));
}
static void stringCharLoad(SpecializedThunkJIT& jit, VM* vm)
{
// load string
jit.loadJSStringArgument(*vm, SpecializedThunkJIT::ThisArgument, SpecializedThunkJIT::regT0);
// Load string length to regT2, and start the process of loading the data pointer into regT0
jit.load32(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringLengthOffset()), SpecializedThunkJIT::regT2);
jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringValueOffset()), SpecializedThunkJIT::regT0);
jit.appendFailure(jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0));
// load index
jit.loadInt32Argument(0, SpecializedThunkJIT::regT1); // regT1 contains the index
// Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large
jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, SpecializedThunkJIT::regT1, SpecializedThunkJIT::regT2));
// Load the character
SpecializedThunkJIT::JumpList is16Bit;
SpecializedThunkJIT::JumpList cont8Bit;
// Load the string flags
jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, StringImpl::flagsOffset()), SpecializedThunkJIT::regT2);
jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, StringImpl::dataOffset()), SpecializedThunkJIT::regT0);
is16Bit.append(jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT2, MacroAssembler::TrustedImm32(StringImpl::flagIs8Bit())));
jit.load8(MacroAssembler::BaseIndex(SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1, MacroAssembler::TimesOne, 0), SpecializedThunkJIT::regT0);
cont8Bit.append(jit.jump());
is16Bit.link(&jit);
jit.load16(MacroAssembler::BaseIndex(SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1, MacroAssembler::TimesTwo, 0), SpecializedThunkJIT::regT0);
cont8Bit.link(&jit);
}
