From 07e6b8d7526380a8a30081354f12f48f39d3464e Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sat, 1 Feb 2025 16:39:48 +0000 Subject: [PATCH] target/arm: Handle FPCR.AH in SVE FTMAD The negation step in the SVE FTMAD insn mustn't negate a NaN when FPCR.AH is set. Pass FPCR.AH to the helper via the SIMD data field, so we can select the correct behaviour. Because the operand is known to be negative, negating the operand is the same as taking the absolute value. Defer this to the muladd operation via flags, so that it happens after NaN detection, which is correct for FPCR.AH. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- target/arm/tcg/sve_helper.c | 42 ++++++++++++++++++++++++++-------- target/arm/tcg/translate-sve.c | 3 ++- 2 files changed, 35 insertions(+), 10 deletions(-) diff --git a/target/arm/tcg/sve_helper.c b/target/arm/tcg/sve_helper.c index bf88bde8a3..c12b2600bd 100644 --- a/target/arm/tcg/sve_helper.c +++ b/target/arm/tcg/sve_helper.c @@ -5134,16 +5134,24 @@ void HELPER(sve_ftmad_h)(void *vd, void *vn, void *vm, 0x3c00, 0xb800, 0x293a, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, }; intptr_t i, opr_sz = simd_oprsz(desc) / sizeof(float16); - intptr_t x = simd_data(desc); + intptr_t x = extract32(desc, SIMD_DATA_SHIFT, 3); + bool fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 3, 1); float16 *d = vd, *n = vn, *m = vm; + for (i = 0; i < opr_sz; i++) { float16 mm = m[i]; intptr_t xx = x; + int flags = 0; + if (float16_is_neg(mm)) { - mm = float16_abs(mm); + if (fpcr_ah) { + flags = float_muladd_negate_product; + } else { + mm = float16_abs(mm); + } xx += 8; } - d[i] = float16_muladd(n[i], mm, coeff[xx], 0, s); + d[i] = float16_muladd(n[i], mm, coeff[xx], flags, s); } } @@ -5157,16 +5165,24 @@ void HELPER(sve_ftmad_s)(void *vd, void *vn, void *vm, 0x37cd37cc, 0x00000000, 0x00000000, 0x00000000, }; intptr_t i, opr_sz = simd_oprsz(desc) / sizeof(float32); - intptr_t x = simd_data(desc); + intptr_t x = extract32(desc, SIMD_DATA_SHIFT, 3); + bool fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 3, 1); float32 *d = vd, *n = vn, *m = vm; + for (i = 0; i < opr_sz; i++) { float32 mm = m[i]; intptr_t xx = x; + int flags = 0; + if (float32_is_neg(mm)) { - mm = float32_abs(mm); + if (fpcr_ah) { + flags = float_muladd_negate_product; + } else { + mm = float32_abs(mm); + } xx += 8; } - d[i] = float32_muladd(n[i], mm, coeff[xx], 0, s); + d[i] = float32_muladd(n[i], mm, coeff[xx], flags, s); } } @@ -5184,16 +5200,24 @@ void HELPER(sve_ftmad_d)(void *vd, void *vn, void *vm, 0x3e21ee96d2641b13ull, 0xbda8f76380fbb401ull, }; intptr_t i, opr_sz = simd_oprsz(desc) / sizeof(float64); - intptr_t x = simd_data(desc); + intptr_t x = extract32(desc, SIMD_DATA_SHIFT, 3); + bool fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 3, 1); float64 *d = vd, *n = vn, *m = vm; + for (i = 0; i < opr_sz; i++) { float64 mm = m[i]; intptr_t xx = x; + int flags = 0; + if (float64_is_neg(mm)) { - mm = float64_abs(mm); + if (fpcr_ah) { + flags = float_muladd_negate_product; + } else { + mm = float64_abs(mm); + } xx += 8; } - d[i] = float64_muladd(n[i], mm, coeff[xx], 0, s); + d[i] = float64_muladd(n[i], mm, coeff[xx], flags, s); } } diff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c index 2dd4605bb2..410087c3fb 100644 --- a/target/arm/tcg/translate-sve.c +++ b/target/arm/tcg/translate-sve.c @@ -3685,7 +3685,8 @@ static gen_helper_gvec_3_ptr * const ftmad_fns[4] = { gen_helper_sve_ftmad_s, gen_helper_sve_ftmad_d, }; TRANS_FEAT_NONSTREAMING(FTMAD, aa64_sve, gen_gvec_fpst_zzz, - ftmad_fns[a->esz], a->rd, a->rn, a->rm, a->imm, + ftmad_fns[a->esz], a->rd, a->rn, a->rm, + a->imm | (s->fpcr_ah << 3), a->esz == MO_16 ? FPST_A64_F16 : FPST_A64) /* -- 2.39.5