[PATCH v2 26/34] target/arm: Handle FPCR.AH in gvec_fcmla[hs]_idx

[Richard Henderson]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/tcg/translate-a64.c |  2 +-
 target/arm/tcg/vec_helper.c    | 44 ++++++++++++++++++++--------------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 3748f7d145..9e751e737a 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -6922,7 +6922,7 @@ static bool trans_FCMLA_vi(DisasContext *s, arg_FCMLA_vi 
*a)
     if (fp_access_check(s)) {
         gen_gvec_op4_fpst(s, a->q, a->rd, a->rn, a->rm, a->rd,
                           a->esz == MO_16 ? FPST_A64_F16 : FPST_A64,
-                          (a->idx << 2) | a->rot, fn);
+                          (s->fpcr_ah << 4) | (a->idx << 2) | a->rot, fn);
     }
     return true;
 }
diff --git a/target/arm/tcg/vec_helper.c b/target/arm/tcg/vec_helper.c
index 76637d072d..964000773a 100644
--- a/target/arm/tcg/vec_helper.c
+++ b/target/arm/tcg/vec_helper.c
@@ -995,29 +995,33 @@ void HELPER(gvec_fcmlah_idx)(void *vd, void *vn, void 
*vm, void *va,
     uintptr_t opr_sz = simd_oprsz(desc);
     float16 *d = vd, *n = vn, *m = vm, *a = va;
     intptr_t flip = extract32(desc, SIMD_DATA_SHIFT, 1);
-    uint32_t neg_imag = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
+    uint32_t negf_imag = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
     intptr_t index = extract32(desc, SIMD_DATA_SHIFT + 2, 2);
-    uint32_t neg_real = flip ^ neg_imag;
+    uint32_t fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 4, 1);
+    uint32_t negf_real = flip ^ negf_imag;
     intptr_t elements = opr_sz / sizeof(float16);
     intptr_t eltspersegment = MIN(16 / sizeof(float16), elements);
+    float16 negx_imag, negx_real;
     intptr_t i, j;
 
-    /* Shift boolean to the sign bit so we can xor to negate.  */
-    neg_real <<= 15;
-    neg_imag <<= 15;
+    /* With AH=0, use negx; with AH=1 use negf. */
+    negx_real = (negf_real & ~fpcr_ah) << 15;
+    negx_imag = (negf_imag & ~fpcr_ah) << 15;
+    negf_real = (negf_real & fpcr_ah ? float_muladd_negate_product : 0);
+    negf_imag = (negf_imag & fpcr_ah ? float_muladd_negate_product : 0);
 
     for (i = 0; i < elements; i += eltspersegment) {
         float16 mr = m[H2(i + 2 * index + 0)];
         float16 mi = m[H2(i + 2 * index + 1)];
-        float16 e1 = neg_real ^ (flip ? mi : mr);
-        float16 e3 = neg_imag ^ (flip ? mr : mi);
+        float16 e1 = negx_real ^ (flip ? mi : mr);
+        float16 e3 = negx_imag ^ (flip ? mr : mi);
 
         for (j = i; j < i + eltspersegment; j += 2) {
             float16 e2 = n[H2(j + flip)];
             float16 e4 = e2;
 
-            d[H2(j)] = float16_muladd(e2, e1, a[H2(j)], 0, fpst);
-            d[H2(j + 1)] = float16_muladd(e4, e3, a[H2(j + 1)], 0, fpst);
+            d[H2(j)] = float16_muladd(e2, e1, a[H2(j)], negf_real, fpst);
+            d[H2(j + 1)] = float16_muladd(e4, e3, a[H2(j + 1)], negf_imag, 
fpst);
         }
     }
     clear_tail(d, opr_sz, simd_maxsz(desc));
@@ -1059,29 +1063,33 @@ void HELPER(gvec_fcmlas_idx)(void *vd, void *vn, void 
*vm, void *va,
     uintptr_t opr_sz = simd_oprsz(desc);
     float32 *d = vd, *n = vn, *m = vm, *a = va;
     intptr_t flip = extract32(desc, SIMD_DATA_SHIFT, 1);
-    uint32_t neg_imag = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
+    uint32_t negf_imag = extract32(desc, SIMD_DATA_SHIFT + 1, 1);
     intptr_t index = extract32(desc, SIMD_DATA_SHIFT + 2, 2);
-    uint32_t neg_real = flip ^ neg_imag;
+    uint32_t fpcr_ah = extract32(desc, SIMD_DATA_SHIFT + 4, 1);
+    uint32_t negf_real = flip ^ negf_imag;
     intptr_t elements = opr_sz / sizeof(float32);
     intptr_t eltspersegment = MIN(16 / sizeof(float32), elements);
+    float32 negx_imag, negx_real;
     intptr_t i, j;
 
-    /* Shift boolean to the sign bit so we can xor to negate.  */
-    neg_real <<= 31;
-    neg_imag <<= 31;
+    /* With AH=0, use negx; with AH=1 use negf. */
+    negx_real = (negf_real & ~fpcr_ah) << 31;
+    negx_imag = (negf_imag & ~fpcr_ah) << 31;
+    negf_real = (negf_real & fpcr_ah ? float_muladd_negate_product : 0);
+    negf_imag = (negf_imag & fpcr_ah ? float_muladd_negate_product : 0);
 
     for (i = 0; i < elements; i += eltspersegment) {
         float32 mr = m[H4(i + 2 * index + 0)];
         float32 mi = m[H4(i + 2 * index + 1)];
-        float32 e1 = neg_real ^ (flip ? mi : mr);
-        float32 e3 = neg_imag ^ (flip ? mr : mi);
+        float32 e1 = negx_real ^ (flip ? mi : mr);
+        float32 e3 = negx_imag ^ (flip ? mr : mi);
 
         for (j = i; j < i + eltspersegment; j += 2) {
             float32 e2 = n[H4(j + flip)];
             float32 e4 = e2;
 
-            d[H4(j)] = float32_muladd(e2, e1, a[H4(j)], 0, fpst);
-            d[H4(j + 1)] = float32_muladd(e4, e3, a[H4(j + 1)], 0, fpst);
+            d[H4(j)] = float32_muladd(e2, e1, a[H4(j)], negf_real, fpst);
+            d[H4(j + 1)] = float32_muladd(e4, e3, a[H4(j + 1)], negf_imag, 
fpst);
         }
     }
     clear_tail(d, opr_sz, simd_maxsz(desc));
-- 
2.43.0