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target/i386: Inline cmpxchg16b

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Use tcg_gen_atomic_cmpxchg_i128 for the atomic case,
and tcg_gen_qemu_ld/st_i128 otherwise.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-11-09 23:53:10 +11:00
parent 326ad06cf5
commit 5f0dd8cd33
3 changed files with 39 additions and 78 deletions
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4
target/i386/helper.h
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@ -66,10 +66,6 @@ DEF_HELPER_1(rsm, void, env)
#endif /* !CONFIG_USER_ONLY */
DEF_HELPER_2(into, void, env, int)
#ifdef TARGET_X86_64
DEF_HELPER_2(cmpxchg16b_unlocked, void, env, tl)
DEF_HELPER_2(cmpxchg16b, void, env, tl)
#endif
DEF_HELPER_FLAGS_1(single_step, TCG_CALL_NO_WG, noreturn, env)
DEF_HELPER_1(rechecking_single_step, void, env)
DEF_HELPER_1(cpuid, void, env)

69
target/i386/tcg/mem_helper.c
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@ -27,75 +27,6 @@
#include "tcg/tcg.h"
#include "helper-tcg.h"
#ifdef TARGET_X86_64
void helper_cmpxchg16b_unlocked(CPUX86State *env, target_ulong a0)
{
uintptr_t ra = GETPC();
Int128 oldv, cmpv, newv;
uint64_t o0, o1;
int eflags;
bool success;
if ((a0 & 0xf) != 0) {
raise_exception_ra(env, EXCP0D_GPF, GETPC());
}
eflags = cpu_cc_compute_all(env, CC_OP);
cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
o0 = cpu_ldq_data_ra(env, a0 + 0, ra);
o1 = cpu_ldq_data_ra(env, a0 + 8, ra);
oldv = int128_make128(o0, o1);
success = int128_eq(oldv, cmpv);
if (!success) {
newv = oldv;
}
cpu_stq_data_ra(env, a0 + 0, int128_getlo(newv), ra);
cpu_stq_data_ra(env, a0 + 8, int128_gethi(newv), ra);
if (success) {
eflags |= CC_Z;
} else {
env->regs[R_EAX] = int128_getlo(oldv);
env->regs[R_EDX] = int128_gethi(oldv);
eflags &= ~CC_Z;
}
CC_SRC = eflags;
}
void helper_cmpxchg16b(CPUX86State *env, target_ulong a0)
{
uintptr_t ra = GETPC();
if ((a0 & 0xf) != 0) {
raise_exception_ra(env, EXCP0D_GPF, ra);
} else if (HAVE_CMPXCHG128) {
int eflags = cpu_cc_compute_all(env, CC_OP);
Int128 cmpv = int128_make128(env->regs[R_EAX], env->regs[R_EDX]);
Int128 newv = int128_make128(env->regs[R_EBX], env->regs[R_ECX]);
int mem_idx = cpu_mmu_index(env, false);
MemOpIdx oi = make_memop_idx(MO_TE | MO_128 | MO_ALIGN, mem_idx);
Int128 oldv = cpu_atomic_cmpxchgo_le_mmu(env, a0, cmpv, newv, oi, ra);
if (int128_eq(oldv, cmpv)) {
eflags |= CC_Z;
} else {
env->regs[R_EAX] = int128_getlo(oldv);
env->regs[R_EDX] = int128_gethi(oldv);
eflags &= ~CC_Z;
}
CC_SRC = eflags;
} else {
cpu_loop_exit_atomic(env_cpu(env), ra);
}
}
#endif
void helper_boundw(CPUX86State *env, target_ulong a0, int v)
{
int low, high;

44
target/i386/tcg/translate.c
View File

@ -3053,15 +3053,49 @@ static void gen_cmpxchg8b(DisasContext *s, CPUX86State *env, int modrm)
#ifdef TARGET_X86_64
static void gen_cmpxchg16b(DisasContext *s, CPUX86State *env, int modrm)
{
MemOp mop = MO_TE | MO_128 | MO_ALIGN;
TCGv_i64 t0, t1;
TCGv_i128 cmp, val;
gen_lea_modrm(env, s, modrm);
if ((s->prefix & PREFIX_LOCK) &&
(tb_cflags(s->base.tb) & CF_PARALLEL)) {
gen_helper_cmpxchg16b(cpu_env, s->A0);
cmp = tcg_temp_new_i128();
val = tcg_temp_new_i128();
tcg_gen_concat_i64_i128(cmp, cpu_regs[R_EAX], cpu_regs[R_EDX]);
tcg_gen_concat_i64_i128(val, cpu_regs[R_EBX], cpu_regs[R_ECX]);
/* Only require atomic with LOCK; non-parallel handled in generator. */
if (s->prefix & PREFIX_LOCK) {
tcg_gen_atomic_cmpxchg_i128(val, s->A0, cmp, val, s->mem_index, mop);
} else {
gen_helper_cmpxchg16b_unlocked(cpu_env, s->A0);
tcg_gen_nonatomic_cmpxchg_i128(val, s->A0, cmp, val, s->mem_index, mop);
}
set_cc_op(s, CC_OP_EFLAGS);
tcg_gen_extr_i128_i64(s->T0, s->T1, val);
tcg_temp_free_i128(cmp);
tcg_temp_free_i128(val);
/* Determine success after the fact. */
t0 = tcg_temp_new_i64();
t1 = tcg_temp_new_i64();
tcg_gen_xor_i64(t0, s->T0, cpu_regs[R_EAX]);
tcg_gen_xor_i64(t1, s->T1, cpu_regs[R_EDX]);
tcg_gen_or_i64(t0, t0, t1);
tcg_temp_free_i64(t1);
/* Update Z. */
gen_compute_eflags(s);
tcg_gen_setcondi_i64(TCG_COND_EQ, t0, t0, 0);
tcg_gen_deposit_tl(cpu_cc_src, cpu_cc_src, t0, ctz32(CC_Z), 1);
tcg_temp_free_i64(t0);
/*
* Extract the result values for the register pair. We may do this
* unconditionally, because on success (Z=1), the old value matches
* the previous value in RDX:RAX.
*/
tcg_gen_mov_i64(cpu_regs[R_EAX], s->T0);
tcg_gen_mov_i64(cpu_regs[R_EDX], s->T1);
}
#endif