From 28048a3d180b3893912344869dfa64c1e6a7d40f Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sat, 1 Feb 2025 16:39:42 +0000 Subject: [PATCH] target/arm: Handle FPCR.AH in FRECPS and FRSQRTS scalar insns Handle the FPCR.AH semantics that we do not change the sign of an input NaN in the FRECPS and FRSQRTS scalar insns, by providing new helper functions that do the CHS part of the operation differently. Since the extra helper functions would be very repetitive if written out longhand, we condense them and the existing non-AH helpers into being emitted via macros. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- target/arm/tcg/helper-a64.c | 117 ++++++++++++--------------------- target/arm/tcg/helper-a64.h | 6 ++ target/arm/tcg/translate-a64.c | 25 +++++-- target/arm/tcg/vec_internal.h | 18 +++++ 4 files changed, 84 insertions(+), 82 deletions(-) diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c index ed5e4a4599..32f0647ca4 100644 --- a/target/arm/tcg/helper-a64.c +++ b/target/arm/tcg/helper-a64.c @@ -38,6 +38,7 @@ #ifdef CONFIG_USER_ONLY #include "user/page-protection.h" #endif +#include "vec_internal.h" /* C2.4.7 Multiply and divide */ /* special cases for 0 and LLONG_MIN are mandated by the standard */ @@ -208,88 +209,52 @@ uint64_t HELPER(neon_cgt_f64)(float64 a, float64 b, float_status *fpst) return -float64_lt(b, a, fpst); } -/* Reciprocal step and sqrt step. Note that unlike the A32/T32 +/* + * Reciprocal step and sqrt step. Note that unlike the A32/T32 * versions, these do a fully fused multiply-add or * multiply-add-and-halve. + * The FPCR.AH == 1 versions need to avoid flipping the sign of NaN. */ - -uint32_t HELPER(recpsf_f16)(uint32_t a, uint32_t b, float_status *fpst) -{ - a = float16_squash_input_denormal(a, fpst); - b = float16_squash_input_denormal(b, fpst); - - a = float16_chs(a); - if ((float16_is_infinity(a) && float16_is_zero(b)) || - (float16_is_infinity(b) && float16_is_zero(a))) { - return float16_two; - } - return float16_muladd(a, b, float16_two, 0, fpst); -} - -float32 HELPER(recpsf_f32)(float32 a, float32 b, float_status *fpst) -{ - a = float32_squash_input_denormal(a, fpst); - b = float32_squash_input_denormal(b, fpst); - - a = float32_chs(a); - if ((float32_is_infinity(a) && float32_is_zero(b)) || - (float32_is_infinity(b) && float32_is_zero(a))) { - return float32_two; - } - return float32_muladd(a, b, float32_two, 0, fpst); -} - -float64 HELPER(recpsf_f64)(float64 a, float64 b, float_status *fpst) -{ - a = float64_squash_input_denormal(a, fpst); - b = float64_squash_input_denormal(b, fpst); - - a = float64_chs(a); - if ((float64_is_infinity(a) && float64_is_zero(b)) || - (float64_is_infinity(b) && float64_is_zero(a))) { - return float64_two; - } - return float64_muladd(a, b, float64_two, 0, fpst); -} - -uint32_t HELPER(rsqrtsf_f16)(uint32_t a, uint32_t b, float_status *fpst) -{ - a = float16_squash_input_denormal(a, fpst); - b = float16_squash_input_denormal(b, fpst); - - a = float16_chs(a); - if ((float16_is_infinity(a) && float16_is_zero(b)) || - (float16_is_infinity(b) && float16_is_zero(a))) { - return float16_one_point_five; - } - return float16_muladd_scalbn(a, b, float16_three, -1, 0, fpst); -} - -float32 HELPER(rsqrtsf_f32)(float32 a, float32 b, float_status *fpst) -{ - a = float32_squash_input_denormal(a, fpst); - b = float32_squash_input_denormal(b, fpst); - - a = float32_chs(a); - if ((float32_is_infinity(a) && float32_is_zero(b)) || - (float32_is_infinity(b) && float32_is_zero(a))) { - return float32_one_point_five; +#define DO_RECPS(NAME, CTYPE, FLOATTYPE, CHSFN) \ + CTYPE HELPER(NAME)(CTYPE a, CTYPE b, float_status *fpst) \ + { \ + a = FLOATTYPE ## _squash_input_denormal(a, fpst); \ + b = FLOATTYPE ## _squash_input_denormal(b, fpst); \ + a = FLOATTYPE ## _ ## CHSFN(a); \ + if ((FLOATTYPE ## _is_infinity(a) && FLOATTYPE ## _is_zero(b)) || \ + (FLOATTYPE ## _is_infinity(b) && FLOATTYPE ## _is_zero(a))) { \ + return FLOATTYPE ## _two; \ + } \ + return FLOATTYPE ## _muladd(a, b, FLOATTYPE ## _two, 0, fpst); \ } - return float32_muladd_scalbn(a, b, float32_three, -1, 0, fpst); -} -float64 HELPER(rsqrtsf_f64)(float64 a, float64 b, float_status *fpst) -{ - a = float64_squash_input_denormal(a, fpst); - b = float64_squash_input_denormal(b, fpst); +DO_RECPS(recpsf_f16, uint32_t, float16, chs) +DO_RECPS(recpsf_f32, float32, float32, chs) +DO_RECPS(recpsf_f64, float64, float64, chs) +DO_RECPS(recpsf_ah_f16, uint32_t, float16, ah_chs) +DO_RECPS(recpsf_ah_f32, float32, float32, ah_chs) +DO_RECPS(recpsf_ah_f64, float64, float64, ah_chs) - a = float64_chs(a); - if ((float64_is_infinity(a) && float64_is_zero(b)) || - (float64_is_infinity(b) && float64_is_zero(a))) { - return float64_one_point_five; - } - return float64_muladd_scalbn(a, b, float64_three, -1, 0, fpst); -} +#define DO_RSQRTSF(NAME, CTYPE, FLOATTYPE, CHSFN) \ + CTYPE HELPER(NAME)(CTYPE a, CTYPE b, float_status *fpst) \ + { \ + a = FLOATTYPE ## _squash_input_denormal(a, fpst); \ + b = FLOATTYPE ## _squash_input_denormal(b, fpst); \ + a = FLOATTYPE ## _ ## CHSFN(a); \ + if ((FLOATTYPE ## _is_infinity(a) && FLOATTYPE ## _is_zero(b)) || \ + (FLOATTYPE ## _is_infinity(b) && FLOATTYPE ## _is_zero(a))) { \ + return FLOATTYPE ## _one_point_five; \ + } \ + return FLOATTYPE ## _muladd_scalbn(a, b, FLOATTYPE ## _three, \ + -1, 0, fpst); \ + } \ + +DO_RSQRTSF(rsqrtsf_f16, uint32_t, float16, chs) +DO_RSQRTSF(rsqrtsf_f32, float32, float32, chs) +DO_RSQRTSF(rsqrtsf_f64, float64, float64, chs) +DO_RSQRTSF(rsqrtsf_ah_f16, uint32_t, float16, ah_chs) +DO_RSQRTSF(rsqrtsf_ah_f32, float32, float32, ah_chs) +DO_RSQRTSF(rsqrtsf_ah_f64, float64, float64, ah_chs) /* Floating-point reciprocal exponent - see FPRecpX in ARM ARM */ uint32_t HELPER(frecpx_f16)(uint32_t a, float_status *fpst) diff --git a/target/arm/tcg/helper-a64.h b/target/arm/tcg/helper-a64.h index ae0424f6de..85023465b7 100644 --- a/target/arm/tcg/helper-a64.h +++ b/target/arm/tcg/helper-a64.h @@ -38,9 +38,15 @@ DEF_HELPER_FLAGS_3(neon_cgt_f64, TCG_CALL_NO_RWG, i64, i64, i64, fpst) DEF_HELPER_FLAGS_3(recpsf_f16, TCG_CALL_NO_RWG, f16, f16, f16, fpst) DEF_HELPER_FLAGS_3(recpsf_f32, TCG_CALL_NO_RWG, f32, f32, f32, fpst) DEF_HELPER_FLAGS_3(recpsf_f64, TCG_CALL_NO_RWG, f64, f64, f64, fpst) +DEF_HELPER_FLAGS_3(recpsf_ah_f16, TCG_CALL_NO_RWG, f16, f16, f16, fpst) +DEF_HELPER_FLAGS_3(recpsf_ah_f32, TCG_CALL_NO_RWG, f32, f32, f32, fpst) +DEF_HELPER_FLAGS_3(recpsf_ah_f64, TCG_CALL_NO_RWG, f64, f64, f64, fpst) DEF_HELPER_FLAGS_3(rsqrtsf_f16, TCG_CALL_NO_RWG, f16, f16, f16, fpst) DEF_HELPER_FLAGS_3(rsqrtsf_f32, TCG_CALL_NO_RWG, f32, f32, f32, fpst) DEF_HELPER_FLAGS_3(rsqrtsf_f64, TCG_CALL_NO_RWG, f64, f64, f64, fpst) +DEF_HELPER_FLAGS_3(rsqrtsf_ah_f16, TCG_CALL_NO_RWG, f16, f16, f16, fpst) +DEF_HELPER_FLAGS_3(rsqrtsf_ah_f32, TCG_CALL_NO_RWG, f32, f32, f32, fpst) +DEF_HELPER_FLAGS_3(rsqrtsf_ah_f64, TCG_CALL_NO_RWG, f64, f64, f64, fpst) DEF_HELPER_FLAGS_2(frecpx_f64, TCG_CALL_NO_RWG, f64, f64, fpst) DEF_HELPER_FLAGS_2(frecpx_f32, TCG_CALL_NO_RWG, f32, f32, fpst) DEF_HELPER_FLAGS_2(frecpx_f16, TCG_CALL_NO_RWG, f16, f16, fpst) diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c index e8db9f39b1..1b6d8598b8 100644 --- a/target/arm/tcg/translate-a64.c +++ b/target/arm/tcg/translate-a64.c @@ -5239,11 +5239,12 @@ static bool do_fp3_scalar(DisasContext *s, arg_rrr_e *a, const FPScalar *f, FPST_A64_F16 : FPST_A64); } -static bool do_fp3_scalar_ah(DisasContext *s, arg_rrr_e *a, const FPScalar *f, - int mergereg) +static bool do_fp3_scalar_ah_2fn(DisasContext *s, arg_rrr_e *a, + const FPScalar *fnormal, const FPScalar *fah, + int mergereg) { - return do_fp3_scalar_with_fpsttype(s, a, f, mergereg, - select_ah_fpst(s, a->esz)); + return do_fp3_scalar_with_fpsttype(s, a, s->fpcr_ah ? fah : fnormal, + mergereg, select_ah_fpst(s, a->esz)); } /* Some insns need to call different helpers when FPCR.AH == 1 */ @@ -5464,14 +5465,26 @@ static const FPScalar f_scalar_frecps = { gen_helper_recpsf_f32, gen_helper_recpsf_f64, }; -TRANS(FRECPS_s, do_fp3_scalar_ah, a, &f_scalar_frecps, a->rn) +static const FPScalar f_scalar_ah_frecps = { + gen_helper_recpsf_ah_f16, + gen_helper_recpsf_ah_f32, + gen_helper_recpsf_ah_f64, +}; +TRANS(FRECPS_s, do_fp3_scalar_ah_2fn, a, + &f_scalar_frecps, &f_scalar_ah_frecps, a->rn) static const FPScalar f_scalar_frsqrts = { gen_helper_rsqrtsf_f16, gen_helper_rsqrtsf_f32, gen_helper_rsqrtsf_f64, }; -TRANS(FRSQRTS_s, do_fp3_scalar_ah, a, &f_scalar_frsqrts, a->rn) +static const FPScalar f_scalar_ah_frsqrts = { + gen_helper_rsqrtsf_ah_f16, + gen_helper_rsqrtsf_ah_f32, + gen_helper_rsqrtsf_ah_f64, +}; +TRANS(FRSQRTS_s, do_fp3_scalar_ah_2fn, a, + &f_scalar_frsqrts, &f_scalar_ah_frsqrts, a->rn) static bool do_fcmp0_s(DisasContext *s, arg_rr_e *a, const FPScalar *f, bool swap) diff --git a/target/arm/tcg/vec_internal.h b/target/arm/tcg/vec_internal.h index 826791523a..6b93b5aeb9 100644 --- a/target/arm/tcg/vec_internal.h +++ b/target/arm/tcg/vec_internal.h @@ -267,6 +267,24 @@ float32 bfdotadd_ebf(float32 sum, uint32_t e1, uint32_t e2, */ bool is_ebf(CPUARMState *env, float_status *statusp, float_status *oddstatusp); +/* + * Negate as for FPCR.AH=1 -- do not negate NaNs. + */ +static inline float16 float16_ah_chs(float16 a) +{ + return float16_is_any_nan(a) ? a : float16_chs(a); +} + +static inline float32 float32_ah_chs(float32 a) +{ + return float32_is_any_nan(a) ? a : float32_chs(a); +} + +static inline float64 float64_ah_chs(float64 a) +{ + return float64_is_any_nan(a) ? a : float64_chs(a); +} + static inline float16 float16_maybe_ah_chs(float16 a, bool fpcr_ah) { return fpcr_ah && float16_is_any_nan(a) ? a : float16_chs(a); -- 2.39.5