Make SVE FABS honour the FPCR.AH "don't negate the sign of a NaN"
semantics.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/tcg/helper-sve.h    | 4 ++++
 target/arm/tcg/sve_helper.c    | 8 ++++++++
 target/arm/tcg/translate-sve.c | 7 ++++++-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/target/arm/tcg/helper-sve.h b/target/arm/tcg/helper-sve.h
index 867a6d96e04..ff12f650c87 100644
--- a/target/arm/tcg/helper-sve.h
+++ b/target/arm/tcg/helper-sve.h
@@ -541,6 +541,10 @@ DEF_HELPER_FLAGS_4(sve_fabs_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_fabs_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_fabs_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 
+DEF_HELPER_FLAGS_4(sve_ah_fabs_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(sve_ah_fabs_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(sve_ah_fabs_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+
 DEF_HELPER_FLAGS_4(sve_fneg_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_fneg_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_fneg_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
diff --git a/target/arm/tcg/sve_helper.c b/target/arm/tcg/sve_helper.c
index 976f3be44e0..5ce7d736475 100644
--- a/target/arm/tcg/sve_helper.c
+++ b/target/arm/tcg/sve_helper.c
@@ -879,6 +879,14 @@ DO_ZPZ(sve_fabs_h, uint16_t, H1_2, DO_FABS)
 DO_ZPZ(sve_fabs_s, uint32_t, H1_4, DO_FABS)
 DO_ZPZ_D(sve_fabs_d, uint64_t, DO_FABS)
 
+#define DO_AH_FABS_H(N) (float16_is_any_nan(N) ? (N) : DO_FABS(N))
+#define DO_AH_FABS_S(N) (float32_is_any_nan(N) ? (N) : DO_FABS(N))
+#define DO_AH_FABS_D(N) (float64_is_any_nan(N) ? (N) : DO_FABS(N))
+
+DO_ZPZ(sve_ah_fabs_h, uint16_t, H1_2, DO_AH_FABS_H)
+DO_ZPZ(sve_ah_fabs_s, uint32_t, H1_4, DO_AH_FABS_S)
+DO_ZPZ_D(sve_ah_fabs_d, uint64_t, DO_AH_FABS_D)
+
 #define DO_FNEG(N)    (N ^ ~((__typeof(N))-1 >> 1))
 
 DO_ZPZ(sve_fneg_h, uint16_t, H1_2, DO_FNEG)
diff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c
index 4d5de2004f0..646d0171d99 100644
--- a/target/arm/tcg/translate-sve.c
+++ b/target/arm/tcg/translate-sve.c
@@ -783,7 +783,12 @@ static gen_helper_gvec_3 * const fabs_fns[4] = {
     NULL,                  gen_helper_sve_fabs_h,
     gen_helper_sve_fabs_s, gen_helper_sve_fabs_d,
 };
-TRANS_FEAT(FABS, aa64_sve, gen_gvec_ool_arg_zpz, fabs_fns[a->esz], a, 0)
+static gen_helper_gvec_3 * const fabs_ah_fns[4] = {
+    NULL,                  gen_helper_sve_ah_fabs_h,
+    gen_helper_sve_ah_fabs_s, gen_helper_sve_ah_fabs_d,
+};
+TRANS_FEAT(FABS, aa64_sve, gen_gvec_ool_arg_zpz,
+           s->fpcr_ah ? fabs_ah_fns[a->esz] : fabs_fns[a->esz], a, 0)
 
 static gen_helper_gvec_3 * const fneg_fns[4] = {
     NULL,                  gen_helper_sve_fneg_h,
-- 
2.34.1