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Improve rewritable consts on s390x (zherczeg#300)
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@zherczeg
zherczeg authored Jan 31, 2025
1 parent f578900 commit a442875
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Showing 2 changed files with 95 additions and 54 deletions.
2 changes: 1 addition & 1 deletion sljit_src/sljitNativePPC_common.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3311,7 +3311,7 @@ SLJIT_API_FUNC_ATTRIBUTE void sljit_set_const(sljit_uw addr, sljit_s32 op, sljit
inst[0] = (inst[0] & 0xffff0000) | IMM(new_constant);
SLJIT_UPDATE_WX_FLAGS(inst, inst + 1, 1);
inst = (sljit_ins *)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
SLJIT_CACHE_FLUSH(inst, inst + 2);
SLJIT_CACHE_FLUSH(inst, inst + 1);
return;

#if (defined SLJIT_CONFIG_PPC_64 && SLJIT_CONFIG_PPC_64)
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147 changes: 94 additions & 53 deletions sljit_src/sljitNativeS390X.c
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Original file line number Diff line number Diff line change
Expand Up @@ -125,11 +125,6 @@ static const sljit_u8 freg_map[SLJIT_NUMBER_OF_FLOAT_REGISTERS + 2] = {
#define F32(r) (R32A((sljit_ins)freg_map[r]))
#define F36(r) (R36A((sljit_ins)freg_map[r]))

struct sljit_s390x_const {
struct sljit_const const_; /* must be first */
sljit_sw init_value; /* required to build literal pool */
};

/* Convert SLJIT register to hardware register. */
static SLJIT_INLINE sljit_gpr gpr(sljit_s32 r)
{
Expand Down Expand Up @@ -983,6 +978,12 @@ static const sljit_ins store_forms[3] = {
0xe30000000024 /* stg */
};

static const sljit_ins store_byte_forms[3] = {
0x42000000 /* stc */,
0xe30000000072 /* stcy */,
0
};

static const sljit_ins load_halfword_forms[3] = {
0x48000000 /* lh */,
0xe30000000078 /* lhy */,
Expand Down Expand Up @@ -1021,6 +1022,13 @@ static SLJIT_INLINE sljit_s32 store_word(struct sljit_compiler *compiler, sljit_
return load_store_op(compiler, src_r, dst, dstw, is_32bit, store_forms);
}

/* May clobber tmp1. */
static SLJIT_INLINE sljit_s32 store_byte(struct sljit_compiler *compiler, sljit_gpr src_r,
sljit_s32 dst, sljit_sw dstw)
{
return load_store_op(compiler, src_r, dst, dstw, 1, store_byte_forms);
}

#undef WHEN

static sljit_s32 emit_move(struct sljit_compiler *compiler,
Expand Down Expand Up @@ -1431,12 +1439,6 @@ SLJIT_API_FUNC_ATTRIBUTE void* sljit_generate_code(struct sljit_compiler *compil
jump = jump->next;
}

const_ = compiler->consts;
while (const_) {
pool_size += sizeof(*pool);
const_ = const_->next;
}

/* pad code size to 8 bytes so is accessible with half word offsets */
/* the literal pool needs to be doubleword aligned */
pad_size = ((ins_size + 7UL) & ~7UL) - ins_size;
Expand Down Expand Up @@ -1531,24 +1533,8 @@ SLJIT_API_FUNC_ATTRIBUTE void* sljit_generate_code(struct sljit_compiler *compil

jump = jump->next;
next_jump_addr = SLJIT_GET_NEXT_ADDRESS(jump);
} else if (next_min_addr == next_const_addr) {
/* update instruction with relative address of constant */
source = (sljit_sw)code_ptr;
offset = (sljit_sw)pool_ptr - source;

SLJIT_ASSERT(!(offset & 0x1));
offset >>= 1; /* halfword (not byte) offset */
SLJIT_ASSERT(is_s32(offset));

ins |= (sljit_ins)offset & 0xffffffff;

/* update address */
const_->addr = (sljit_uw)pool_ptr;

/* store initial value into pool and update pool address */
*(pool_ptr++) = (sljit_uw)(((struct sljit_s390x_const*)const_)->init_value);

/* move to next constant */
} else if (next_min_addr == next_const_addr) {
const_->addr = (sljit_uw)code_ptr;
const_ = const_->next;
next_const_addr = SLJIT_GET_NEXT_ADDRESS(const_);
}
Expand Down Expand Up @@ -4459,40 +4445,52 @@ SLJIT_API_FUNC_ATTRIBUTE sljit_s32 sljit_emit_atomic_store(struct sljit_compiler
/* Other instructions */
/* --------------------------------------------------------------------- */

/* On s390x we build a literal pool to hold constants. This has two main
advantages:
1. we only need one instruction in the instruction stream (LGRL)
2. we can store 64 bit addresses and use 32 bit offsets
To retrofit the extra information needed to build the literal pool we
add a new sljit_s390x_const struct that contains the initial value but
can still be cast to a sljit_const. */

SLJIT_API_FUNC_ATTRIBUTE struct sljit_const* sljit_emit_const(struct sljit_compiler *compiler, sljit_s32 dst, sljit_sw dstw, sljit_sw init_value)
SLJIT_API_FUNC_ATTRIBUTE struct sljit_const* sljit_emit_const(struct sljit_compiler *compiler, sljit_s32 op,
sljit_s32 dst, sljit_sw dstw,
sljit_sw init_value)
{
struct sljit_s390x_const *const_;
struct sljit_const *const_;
sljit_gpr dst_r;
int is_32 = 0;

CHECK_ERROR_PTR();
CHECK_PTR(check_sljit_emit_const(compiler, dst, dstw, init_value));
CHECK_PTR(check_sljit_emit_const(compiler, op, dst, dstw, init_value));
ADJUST_LOCAL_OFFSET(dst, dstw);

const_ = (struct sljit_s390x_const*)ensure_abuf(compiler,
sizeof(struct sljit_s390x_const));
const_ = (struct sljit_const*)ensure_abuf(compiler, sizeof(struct sljit_const));
PTR_FAIL_IF(!const_);
set_const((struct sljit_const*)const_, compiler);
const_->init_value = init_value;

dst_r = FAST_IS_REG(dst) ? gpr(dst & REG_MASK) : tmp0;
if (have_genext())
PTR_FAIL_IF(push_inst(compiler, lgrl(dst_r, 0)));
else {
PTR_FAIL_IF(push_inst(compiler, larl(tmp1, 0)));
PTR_FAIL_IF(push_inst(compiler, lg(dst_r, 0, r0, tmp1)));

switch (GET_OPCODE(op)) {
case SLJIT_MOV_U8:
if (init_value & 0x100)
init_value |= 0xff00;
else
init_value &= 0xff;

PTR_FAIL_IF(push_inst(compiler, 0xa7090000 /* lghi */ | R20A(dst_r) | (sljit_ins)(init_value & 0xffff)));

if (dst & SLJIT_MEM)
PTR_FAIL_IF(store_byte(compiler, dst_r, dst, dstw));
return (struct sljit_const*)const_;

case SLJIT_MOV32:
is_32 = 1;
/* fallthrough */
case SLJIT_MOV_S32:
PTR_FAIL_IF(push_inst(compiler, 0xc00100000000 /* lgfi */ | R36A(dst_r) | (sljit_ins)(init_value & 0xffffffff)));
break;

default:
PTR_FAIL_IF(push_inst(compiler, 0xc00f00000000 /* llilf */ | R36A(dst_r) | (sljit_ins)(init_value & 0xffffffff)));
PTR_FAIL_IF(push_inst(compiler, 0xc00800000000 /* iihf */ | R36A(dst_r) | (sljit_ins)((init_value >> 32) & 0xffffffff)));
break;
}

if (dst & SLJIT_MEM)
PTR_FAIL_IF(store_word(compiler, dst_r, dst, dstw, 0 /* always 64-bit */));
PTR_FAIL_IF(store_word(compiler, dst_r, dst, dstw, is_32));

return (struct sljit_const*)const_;
}
Expand All @@ -4509,9 +4507,52 @@ SLJIT_API_FUNC_ATTRIBUTE void sljit_set_jump_addr(sljit_uw addr, sljit_uw new_ta
SLJIT_CACHE_FLUSH(ptr, ptr + 1);
}

SLJIT_API_FUNC_ATTRIBUTE void sljit_set_const(sljit_uw addr, sljit_sw new_constant, sljit_sw executable_offset)
SLJIT_API_FUNC_ATTRIBUTE void sljit_set_const(sljit_uw addr, sljit_s32 op, sljit_sw new_constant, sljit_sw executable_offset)
{
sljit_set_jump_addr(addr, (sljit_uw)new_constant, executable_offset);
sljit_u16 *inst = (sljit_u16*)addr;
SLJIT_UNUSED_ARG(executable_offset);

switch (GET_OPCODE(op)) {
case SLJIT_MOV_U8:
SLJIT_ASSERT((inst[0] & 0xff0f) == 0xa709 /* lghi */);

if (new_constant & 0x100)
new_constant |= 0xff00;
else
new_constant &= 0xff;

SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 0);
inst[1] = (sljit_u16)new_constant;
SLJIT_UPDATE_WX_FLAGS(inst, inst + 2, 1);
inst = (sljit_u16*)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
SLJIT_CACHE_FLUSH(inst, inst + 2);
return;

case SLJIT_MOV32:
case SLJIT_MOV_S32:
SLJIT_ASSERT((inst[0] & 0xff0f) == 0xc001 /* lgfi */);

SLJIT_UPDATE_WX_FLAGS(inst, inst + 3, 0);
inst[1] = (sljit_u16)(new_constant >> 16);
inst[2] = (sljit_u16)new_constant;
SLJIT_UPDATE_WX_FLAGS(inst, inst + 3, 1);
inst = (sljit_u16*)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
SLJIT_CACHE_FLUSH(inst, inst + 3);
return;

default:
SLJIT_ASSERT((inst[0] & 0xff0f) == 0xc00f /* llilf */ && (inst[3] & 0xff0f) == 0xc008 /* iihf */);

SLJIT_UPDATE_WX_FLAGS(inst, inst + 6, 0);
inst[1] = (sljit_u16)(new_constant >> 16);
inst[2] = (sljit_u16)new_constant;
inst[4] = (sljit_u16)(new_constant >> 48);
inst[5] = (sljit_u16)(new_constant >> 32);
SLJIT_UPDATE_WX_FLAGS(inst, inst + 6, 1);
inst = (sljit_u16*)SLJIT_ADD_EXEC_OFFSET(inst, executable_offset);
SLJIT_CACHE_FLUSH(inst, inst + 6);
return;
}
}

SLJIT_API_FUNC_ATTRIBUTE struct sljit_jump* sljit_emit_mov_addr(struct sljit_compiler *compiler, sljit_s32 dst, sljit_sw dstw)
Expand Down

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