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microblaze: Improve addkc

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* Optimize handling when carry is not updated.
* Optimize handling for adds with nop semantics.
* Move code from helper_addkc to the translator making
  helper_addkc PURE and CONST.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
This commit is contained in:
Edgar E. Iglesias 2011-01-22 12:02:53 +01:00
parent 2accfb5fa6
commit 40cbf5b709
3 changed files with 46 additions and 27 deletions
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2
target-microblaze/helper.h
View file

@ -2,7 +2,7 @@
DEF_HELPER_1(raise_exception, void, i32)
DEF_HELPER_0(debug, void)
DEF_HELPER_4(addkc, i32, i32, i32, i32, i32)
DEF_HELPER_FLAGS_3(addkc, TCG_CALL_PURE | TCG_CALL_CONST, i32, i32, i32, i32)
DEF_HELPER_4(subkc, i32, i32, i32, i32, i32)
DEF_HELPER_2(cmp, i32, i32, i32)
DEF_HELPER_2(cmpu, i32, i32, i32)

20
target-microblaze/op_helper.c
View file

@ -128,26 +128,14 @@ uint32_t helper_cmpu(uint32_t a, uint32_t b)
return t;
}
uint32_t helper_addkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)
uint32_t helper_addkc(uint32_t a, uint32_t b, uint32_t cf)
{
uint32_t d, cf = 0, ncf;
uint32_t d, ncf;
if (c)
cf = env->sregs[SR_MSR] >> 31;
assert(cf == 0 || cf == 1);
d = a + b + cf;
if (!k) {
ncf = compute_carry(a, b, cf);
assert(ncf == 0 || ncf == 1);
if (ncf)
env->sregs[SR_MSR] |= MSR_C | MSR_CC;
else
env->sregs[SR_MSR] &= ~(MSR_C | MSR_CC);
}
D(qemu_log("%x = %x + %x cf=%d ncf=%d k=%d c=%d\n",
d, a, b, cf, ncf, k, c));
return d;
ncf = compute_carry(a, b, cf);
return ncf;
}
uint32_t helper_subkc(uint32_t a, uint32_t b, uint32_t k, uint32_t c)

51
target-microblaze/translate.c
View file

@ -193,6 +193,7 @@ static inline TCGv *dec_alu_op_b(DisasContext *dc)
static void dec_add(DisasContext *dc)
{
unsigned int k, c;
TCGv cf;
k = dc->opcode & 4;
c = dc->opcode & 2;
@ -201,17 +202,47 @@ static void dec_add(DisasContext *dc)
dc->type_b ? "i" : "", k ? "k" : "", c ? "c" : "",
dc->rd, dc->ra, dc->rb);
if (k && !c && dc->rd)
tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));
else if (dc->rd)
gen_helper_addkc(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)),
tcg_const_tl(k), tcg_const_tl(c));
else {
TCGv d = tcg_temp_new();
gen_helper_addkc(d, cpu_R[dc->ra], *(dec_alu_op_b(dc)),
tcg_const_tl(k), tcg_const_tl(c));
tcg_temp_free(d);
/* Take care of the easy cases first. */
if (k) {
/* k - keep carry, no need to update MSR. */
/* If rd == r0, it's a nop. */
if (dc->rd) {
tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));
if (c) {
/* c - Add carry into the result. */
cf = tcg_temp_new();
read_carry(dc, cf);
tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->rd], cf);
tcg_temp_free(cf);
}
}
return;
}
/* From now on, we can assume k is zero. So we need to update MSR. */
/* Extract carry. */
cf = tcg_temp_new();
if (c) {
read_carry(dc, cf);
} else {
tcg_gen_movi_tl(cf, 0);
}
if (dc->rd) {
TCGv ncf = tcg_temp_new();
gen_helper_addkc(ncf, cpu_R[dc->ra], *(dec_alu_op_b(dc)), cf);
tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));
tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->rd], cf);
write_carry(dc, ncf);
tcg_temp_free(ncf);
} else {
gen_helper_addkc(cf, cpu_R[dc->ra], *(dec_alu_op_b(dc)),
tcg_const_tl(cf));
write_carry(dc, cf);
}
tcg_temp_free(cf);
}
static void dec_sub(DisasContext *dc)