Honour the FPCR.AH "don't negate the sign of a NaN" semantics in
FMLSL. We pass in the value of FPCR.AH in the SIMD data field, and
use this to determine whether we should suppress the negation for
NaN inputs.
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
target/arm/tcg/translate-a64.c | 4 ++--
target/arm/tcg/vec_helper.c | 28 ++++++++++++++++++++++++----
2 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 0827dff16b2..e22c2a148ab 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -5968,7 +5968,7 @@ TRANS(FMINNMP_v, do_fp3_vector, a, 0, f_vector_fminnmp)
static bool do_fmlal(DisasContext *s, arg_qrrr_e *a, bool is_s, bool is_2)
{
if (fp_access_check(s)) {
- int data = (is_2 << 1) | is_s;
+ int data = (s->fpcr_ah << 2) | (is_2 << 1) | is_s;
tcg_gen_gvec_3_ptr(vec_full_reg_offset(s, a->rd),
vec_full_reg_offset(s, a->rn),
vec_full_reg_offset(s, a->rm), tcg_env,
@@ -6738,7 +6738,7 @@ TRANS(FMLS_vi, do_fmla_vector_idx, a, true)
static bool do_fmlal_idx(DisasContext *s, arg_qrrx_e *a, bool is_s, bool is_2)
{
if (fp_access_check(s)) {
- int data = (a->idx << 2) | (is_2 << 1) | is_s;
+ int data = (s->fpcr_ah << 5) | (a->idx << 2) | (is_2 << 1) | is_s;
tcg_gen_gvec_3_ptr(vec_full_reg_offset(s, a->rd),
vec_full_reg_offset(s, a->rn),
vec_full_reg_offset(s, a->rm), tcg_env,
diff --git a/target/arm/tcg/vec_helper.c b/target/arm/tcg/vec_helper.c
index 382b5da4a9c..aa42c50f9fe 100644
--- a/target/arm/tcg/vec_helper.c
+++ b/target/arm/tcg/vec_helper.c
@@ -2083,6 +2083,26 @@ static uint64_t load4_f16(uint64_t *ptr, int is_q, int
is_2)
return ptr[is_q & is_2] >> ((is_2 & ~is_q) << 5);
}
+static uint64_t neg4_f16(uint64_t v, bool fpcr_ah)
+{
+ /*
+ * Negate all inputs for FMLSL at once. This is slightly complicated
+ * by the need to avoid flipping the sign of a NaN when FPCR.AH == 1
+ */
+ uint64_t mask = 0x8000800080008000ull;
+ if (fpcr_ah) {
+ uint64_t tmp = v, signbit = 0x8000;
+ for (int i = 0; i < 4; i++) {
+ if (float16_is_any_nan(extract64(tmp, 0, 16))) {
+ mask ^= signbit;
+ }
+ tmp >>= 16;
+ signbit <<= 16;
+ }
+ }
+ return v ^ mask;
+}
+
/*
* Note that FMLAL requires oprsz == 8 or oprsz == 16,
* as there is not yet SVE versions that might use blocking.
@@ -2094,6 +2114,7 @@ static void do_fmlal(float32 *d, void *vn, void *vm,
float_status *fpst,
intptr_t i, oprsz = simd_oprsz(desc);
int is_s = extract32(desc, SIMD_DATA_SHIFT, 1);
int is_2 = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
+ bool fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 2, 1);
int is_q = oprsz == 16;
uint64_t n_4, m_4;
@@ -2101,9 +2122,8 @@ static void do_fmlal(float32 *d, void *vn, void *vm,
float_status *fpst,
n_4 = load4_f16(vn, is_q, is_2);
m_4 = load4_f16(vm, is_q, is_2);
- /* Negate all inputs for FMLSL at once. */
if (is_s) {
- n_4 ^= 0x8000800080008000ull;
+ n_4 = neg4_f16(n_4, fpcr_ah);
}
for (i = 0; i < oprsz / 4; i++) {
@@ -2155,6 +2175,7 @@ static void do_fmlal_idx(float32 *d, void *vn, void *vm,
float_status *fpst,
int is_s = extract32(desc, SIMD_DATA_SHIFT, 1);
int is_2 = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
int index = extract32(desc, SIMD_DATA_SHIFT + 2, 3);
+ bool fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 5, 1);
int is_q = oprsz == 16;
uint64_t n_4;
float32 m_1;
@@ -2162,9 +2183,8 @@ static void do_fmlal_idx(float32 *d, void *vn, void *vm,
float_status *fpst,
/* Pre-load all of the f16 data, avoiding overlap issues. */
n_4 = load4_f16(vn, is_q, is_2);
- /* Negate all inputs for FMLSL at once. */
if (is_s) {
- n_4 ^= 0x8000800080008000ull;
+ n_4 = neg4_f16(n_4, fpcr_ah);
}
m_1 = float16_to_float32_by_bits(((float16 *)vm)[H2(index)], fz16);
--
2.34.1
