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gen_pop/gen_push: Avoid some unnecessary locals after registers-in-locals

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This commit is contained in:
Fabian 2018-12-27 19:30:37 +01:00
parent ce10336747
commit ac9ef7d447
1 changed files with 59 additions and 47 deletions
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106
src/rust/codegen.rs
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@ -823,7 +823,6 @@ pub fn gen_jmp_rel16(builder: &mut WasmBuilder, rel16: u16) {
pub fn gen_pop16_ss16(ctx: &mut JitContext) {
// sp = segment_offsets[SS] + reg16[SP] (or just reg16[SP] if has_flat_segmentation)
gen_get_reg16(ctx, regs::SP);
let sp_local = ctx.builder.tee_new_local();
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
@ -836,20 +835,17 @@ pub fn gen_pop16_ss16(ctx: &mut JitContext) {
gen_safe_read16(ctx);
// reg16[SP] += 2;
ctx.builder.instruction_body.get_local(&sp_local);
gen_get_reg16(ctx, regs::SP);
ctx.builder.instruction_body.const_i32(2);
ctx.builder.instruction_body.add_i32();
gen_set_reg16(ctx, regs::SP);
ctx.builder.free_local(sp_local);
// return value is already on stack
}
pub fn gen_pop16_ss32(ctx: &mut JitContext) {
// esp = segment_offsets[SS] + reg32s[ESP] (or just reg32s[ESP] if has_flat_segmentation)
gen_get_reg32(ctx, regs::ESP);
let esp_local = ctx.builder.tee_new_local();
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
@ -862,11 +858,10 @@ pub fn gen_pop16_ss32(ctx: &mut JitContext) {
gen_safe_read16(ctx);
// reg32s[ESP] += 2;
ctx.builder.instruction_body.get_local(&esp_local);
gen_get_reg32(ctx, regs::ESP);
ctx.builder.instruction_body.const_i32(2);
ctx.builder.instruction_body.add_i32();
gen_set_reg32(ctx, regs::ESP);
ctx.builder.free_local(esp_local);
// return value is already on stack
}
@ -883,7 +878,6 @@ pub fn gen_pop16(ctx: &mut JitContext) {
pub fn gen_pop32s_ss16(ctx: &mut JitContext) {
// sp = reg16[SP]
gen_get_reg16(ctx, regs::SP);
let local_sp = ctx.builder.tee_new_local();
// result = safe_read32s(segment_offsets[SS] + sp) (or just sp if has_flat_segmentation)
if !ctx.cpu.has_flat_segmentation() {
@ -896,20 +890,17 @@ pub fn gen_pop32s_ss16(ctx: &mut JitContext) {
gen_safe_read32(ctx);
// reg16[SP] = sp + 4;
ctx.builder.instruction_body.get_local(&local_sp);
gen_get_reg16(ctx, regs::SP);
ctx.builder.instruction_body.const_i32(4);
ctx.builder.instruction_body.add_i32();
gen_set_reg16(ctx, regs::SP);
ctx.builder.free_local(local_sp);
// return value is already on stack
}
pub fn gen_pop32s_ss32(ctx: &mut JitContext) {
// esp = reg32s[ESP]
gen_get_reg32(ctx, regs::ESP);
let local_esp = ctx.builder.tee_new_local();
// result = safe_read32s(segment_offsets[SS] + esp) (or just esp if has_flat_segmentation)
if !ctx.cpu.has_flat_segmentation() {
@ -921,13 +912,11 @@ pub fn gen_pop32s_ss32(ctx: &mut JitContext) {
gen_safe_read32(ctx);
// reg32s[ESP] = esp + 4;
ctx.builder.instruction_body.get_local(&local_esp);
gen_get_reg32(ctx, regs::ESP);
ctx.builder.instruction_body.const_i32(4);
ctx.builder.instruction_body.add_i32();
gen_set_reg32(ctx, regs::ESP);
ctx.builder.free_local(local_esp);
// return value is already on stack
}
@ -1056,23 +1045,35 @@ pub fn gen_push16(ctx: &mut JitContext, value_local: &WasmLocal) {
ctx.builder.instruction_body.const_i32(2);
ctx.builder.instruction_body.sub_i32();
let reg_updated_local = ctx.builder.tee_new_local();
if !ctx.cpu.ssize_32() {
ctx.builder.instruction_body.const_i32(0xFFFF);
ctx.builder.instruction_body.and_i32();
}
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
.instruction_body
.load_aligned_i32(global_pointers::get_seg_offset(regs::SS));
ctx.builder.instruction_body.add_i32();
}
let reg_updated_local = if !ctx.cpu.ssize_32() || !ctx.cpu.has_flat_segmentation() {
let reg_updated_local = ctx.builder.tee_new_local();
if !ctx.cpu.ssize_32() {
ctx.builder.instruction_body.const_i32(0xFFFF);
ctx.builder.instruction_body.and_i32();
}
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
.instruction_body
.load_aligned_i32(global_pointers::get_seg_offset(regs::SS));
ctx.builder.instruction_body.add_i32();
}
let sp_local = ctx.builder.set_new_local();
gen_safe_write16(ctx, &sp_local, &value_local);
ctx.builder.free_local(sp_local);
ctx.builder.instruction_body.get_local(&reg_updated_local);
reg_updated_local
}
else {
// short path: The address written to is equal to ESP/SP minus two
let reg_updated_local = ctx.builder.tee_new_local();
gen_safe_write16(ctx, &reg_updated_local, &value_local);
reg_updated_local
};
let sp_local = ctx.builder.set_new_local();
gen_safe_write16(ctx, &sp_local, &value_local);
ctx.builder.free_local(sp_local);
ctx.builder.instruction_body.get_local(&reg_updated_local);
if ctx.cpu.ssize_32() {
gen_set_reg32(ctx, regs::ESP);
}
@ -1092,25 +1093,36 @@ pub fn gen_push32(ctx: &mut JitContext, value_local: &WasmLocal) {
ctx.builder.instruction_body.const_i32(4);
ctx.builder.instruction_body.sub_i32();
if !ctx.cpu.ssize_32() {
ctx.builder.instruction_body.const_i32(0xFFFF);
ctx.builder.instruction_body.and_i32();
let new_sp_local = if !ctx.cpu.ssize_32() || !ctx.cpu.has_flat_segmentation() {
let new_sp_local = ctx.builder.tee_new_local();
if !ctx.cpu.ssize_32() {
ctx.builder.instruction_body.const_i32(0xFFFF);
ctx.builder.instruction_body.and_i32();
}
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
.instruction_body
.load_aligned_i32(global_pointers::get_seg_offset(regs::SS));
ctx.builder.instruction_body.add_i32();
}
let sp_local = ctx.builder.set_new_local();
gen_safe_write32(ctx, &sp_local, &value_local);
ctx.builder.free_local(sp_local);
ctx.builder.instruction_body.get_local(&new_sp_local);
new_sp_local
}
let new_sp_local = ctx.builder.tee_new_local();
else {
// short path: The address written to is equal to ESP/SP minus four
let new_sp_local = ctx.builder.tee_new_local();
gen_safe_write32(ctx, &new_sp_local, &value_local);
new_sp_local
};
if !ctx.cpu.has_flat_segmentation() {
ctx.builder
.instruction_body
.load_aligned_i32(global_pointers::get_seg_offset(regs::SS));
ctx.builder.instruction_body.add_i32();
}
let sp_local = ctx.builder.set_new_local();
gen_safe_write32(ctx, &sp_local, &value_local);
ctx.builder.free_local(sp_local);
ctx.builder.instruction_body.get_local(&new_sp_local);
if ctx.cpu.ssize_32() {
gen_set_reg32(ctx, regs::ESP);
}