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jit scasb

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This commit is contained in:
Fabian 2021-04-09 20:37:55 -05:00
parent 2e25308f17
commit 7b66ae874d
4 changed files with 42 additions and 5 deletions
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2
gen/x86_table.js
View file

@ -246,7 +246,7 @@ const encodings = [
{ opcode: 0xF2AD, block_boundary: 1, custom: 1, is_string: 1, os: 1, },
{ opcode: 0xF3AD, block_boundary: 1, custom: 1, is_string: 1, os: 1, },
{ opcode: 0xAE, block_boundary: 1, custom: 1, is_string: 1, },
{ opcode: 0xAE, block_boundary: 0, custom: 1, is_string: 1, },
{ opcode: 0xF2AE, block_boundary: 1, custom: 1, is_string: 1, },
{ opcode: 0xF3AE, block_boundary: 1, custom: 1, is_string: 1, },
{ opcode: 0xAF, block_boundary: 1, custom: 1, is_string: 1, os: 1, },

1
src/rust/cpu/string.rs
View file

@ -593,7 +593,6 @@ pub unsafe fn scasw_repnz(is_asize_32: bool) {
pub unsafe fn scasd_repnz(is_asize_32: bool) {
string_instruction(is_asize_32, 0, Instruction::Scas, Size::D, Rep::NZ)
}
#[no_mangle]
pub unsafe fn scasb_no_rep(is_asize_32: bool) {
string_instruction(is_asize_32, 0, Instruction::Scas, Size::B, Rep::None)
}

32
src/rust/jit_instructions.rs
View file

@ -8,7 +8,7 @@ use cpu::cpu::{
};
use cpu::global_pointers;
use jit::{Instruction, InstructionOperand, JitContext};
use modrm::{jit_add_seg_offset, ModrmByte};
use modrm::{jit_add_seg_offset, jit_add_seg_offset_no_override, ModrmByte};
use prefix::SEG_PREFIX_ZERO;
use prefix::{PREFIX_66, PREFIX_67, PREFIX_F2, PREFIX_F3};
use regs;
@ -4489,6 +4489,36 @@ fn gen_string_ins(ctx: &mut JitContext, ins: String, size: u8, prefix: u8) {
}
return;
},
(String::SCAS, 8) => {
if ctx.cpu.asize_32() {
codegen::gen_get_reg32(ctx, regs::EDI);
}
else {
codegen::gen_get_reg16(ctx, regs::EDI);
}
jit_add_seg_offset_no_override(ctx, regs::ES);
let address_local = ctx.builder.set_new_local();
codegen::gen_safe_read8(ctx, &address_local);
ctx.builder.free_local(address_local);
let value = ctx.builder.set_new_local();
gen_cmp8(
ctx,
&ctx.reg(regs::EAX),
&LocalOrImmediate::WasmLocal(&value),
);
ctx.builder.free_local(value);
codegen::gen_get_reg32(ctx, regs::EDI);
get_direction(ctx);
ctx.builder.add_i32();
if ctx.cpu.asize_32() {
codegen::gen_set_reg32(ctx, regs::EDI);
}
else {
codegen::gen_set_reg16(ctx, regs::EDI);
}
return;
},
_ => {},
}
}

12
src/rust/modrm.rs
View file

@ -254,9 +254,17 @@ fn can_optimize_get_seg(ctx: &mut JitContext, segment: u32) -> bool {
pub fn jit_add_seg_offset(ctx: &mut JitContext, default_segment: u32) {
let prefix = ctx.cpu.prefixes & PREFIX_MASK_SEGMENT;
let seg = if prefix != 0 { prefix - 1 } else { default_segment };
if can_optimize_get_seg(ctx, seg) || prefix == SEG_PREFIX_ZERO {
if prefix == SEG_PREFIX_ZERO {
return;
}
let seg = if prefix != 0 { prefix - 1 } else { default_segment };
jit_add_seg_offset_no_override(ctx, seg);
}
pub fn jit_add_seg_offset_no_override(ctx: &mut JitContext, seg: u32) {
if can_optimize_get_seg(ctx, seg) {
codegen::gen_profiler_stat_increment(ctx.builder, profiler::stat::SEG_OFFSET_OPTIMISED);
return;
}