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target/ppc: Add helpers for fmadds et al 

Use float64r32_muladd.  Fixes a double-rounding issue with performing
the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-29-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This commit is contained in:
Richard Henderson 2021-12-17 17:57:16 +01:00 committed by Cédric Le Goater
parent 42636fb923
commit d04ca895dc
3 changed files with 25 additions and 9 deletions
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17
target/ppc/fpu_helper.c
View File

@ -705,10 +705,25 @@ static float64 do_fmadd(CPUPPCState *env, float64 a, float64 b,
return ret;
}
static uint64_t do_fmadds(CPUPPCState *env, float64 a, float64 b,
float64 c, int madd_flags, uintptr_t retaddr)
{
float64 ret = float64r32_muladd(a, b, c, madd_flags, &env->fp_status);
int flags = get_float_exception_flags(&env->fp_status);
if (unlikely(flags & float_flag_invalid)) {
float_invalid_op_madd(env, flags, 1, retaddr);
}
return ret;
}
#define FPU_FMADD(op, madd_flags) \
uint64_t helper_##op(CPUPPCState *env, uint64_t arg1, \
uint64_t arg2, uint64_t arg3) \
{ return do_fmadd(env, arg1, arg2, arg3, madd_flags, GETPC()); }
{ return do_fmadd(env, arg1, arg2, arg3, madd_flags, GETPC()); } \
uint64_t helper_##op##s(CPUPPCState *env, uint64_t arg1, \
uint64_t arg2, uint64_t arg3) \
{ return do_fmadds(env, arg1, arg2, arg3, madd_flags, GETPC()); }
#define MADD_FLGS 0
#define MSUB_FLGS float_muladd_negate_c

4
target/ppc/helper.h
View File

@ -101,6 +101,10 @@ DEF_HELPER_4(fmadd, i64, env, i64, i64, i64)
DEF_HELPER_4(fmsub, i64, env, i64, i64, i64)
DEF_HELPER_4(fnmadd, i64, env, i64, i64, i64)
DEF_HELPER_4(fnmsub, i64, env, i64, i64, i64)
DEF_HELPER_4(fmadds, i64, env, i64, i64, i64)
DEF_HELPER_4(fmsubs, i64, env, i64, i64, i64)
DEF_HELPER_4(fnmadds, i64, env, i64, i64, i64)
DEF_HELPER_4(fnmsubs, i64, env, i64, i64, i64)
DEF_HELPER_2(fsqrt, f64, env, f64)
DEF_HELPER_2(fre, i64, env, i64)
DEF_HELPER_2(fres, i64, env, i64)

13
target/ppc/translate/fp-impl.c.inc
View File

@ -31,7 +31,7 @@ static void gen_set_cr1_from_fpscr(DisasContext *ctx)
#endif
/*** Floating-Point arithmetic ***/
#define _GEN_FLOAT_ACB(name, op, op1, op2, isfloat, set_fprf, type) \
#define _GEN_FLOAT_ACB(name, op1, op2, set_fprf, type) \
static void gen_f##name(DisasContext *ctx) \
{ \
TCGv_i64 t0; \
@ -50,10 +50,7 @@ static void gen_f##name(DisasContext *ctx) \
get_fpr(t0, rA(ctx->opcode)); \
get_fpr(t1, rC(ctx->opcode)); \
get_fpr(t2, rB(ctx->opcode)); \
gen_helper_f##op(t3, cpu_env, t0, t1, t2); \
if (isfloat) { \
gen_helper_frsp(t3, cpu_env, t3); \
} \
gen_helper_f##name(t3, cpu_env, t0, t1, t2); \
set_fpr(rD(ctx->opcode), t3); \
if (set_fprf) { \
gen_compute_fprf_float64(t3); \
@ -68,8 +65,8 @@ static void gen_f##name(DisasContext *ctx) \
}
#define GEN_FLOAT_ACB(name, op2, set_fprf, type) \
_GEN_FLOAT_ACB(name, name, 0x3F, op2, 0, set_fprf, type); \
_GEN_FLOAT_ACB(name##s, name, 0x3B, op2, 1, set_fprf, type);
_GEN_FLOAT_ACB(name, 0x3F, op2, set_fprf, type); \
_GEN_FLOAT_ACB(name##s, 0x3B, op2, set_fprf, type);
#define _GEN_FLOAT_AB(name, op, op1, op2, inval, isfloat, set_fprf, type) \
static void gen_f##name(DisasContext *ctx) \
@ -233,7 +230,7 @@ static void gen_frsqrtes(DisasContext *ctx)
}
/* fsel */
_GEN_FLOAT_ACB(sel, sel, 0x3F, 0x17, 0, 0, PPC_FLOAT_FSEL);
_GEN_FLOAT_ACB(sel, 0x3F, 0x17, 0, PPC_FLOAT_FSEL);
/* fsub - fsubs */
GEN_FLOAT_AB(sub, 0x14, 0x000007C0, 1, PPC_FLOAT);
/* Optional: */