From 8ac9e3cff2c700cde1d81e89e4c89c5d9d5f4e8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Thu, 8 Mar 2018 18:32:16 -0500
Subject: [PATCH] arm/translate-a64: add FP16 FCMxx (zero) to
 simd_two_reg_misc_fp16

I re-use the existing handle_2misc_fcmp_zero handler and tweak it
slightly to deal with the half-precision case.

Backports commit 7d4dd1a73a023f75c893623710e43743501b318e from qemu
---
 qemu/target/arm/translate-a64.c | 80 +++++++++++++++++++++++----------
 1 file changed, 57 insertions(+), 23 deletions(-)

diff --git a/qemu/target/arm/translate-a64.c b/qemu/target/arm/translate-a64.c
index 1cf59571..791ec0ff 100644
--- a/qemu/target/arm/translate-a64.c
+++ b/qemu/target/arm/translate-a64.c
@@ -7954,14 +7954,14 @@ static void handle_2misc_fcmp_zero(DisasContext *s, int opcode,
                                    int size, int rn, int rd)
 {
     TCGContext *tcg_ctx = s->uc->tcg_ctx;
-    bool is_double = (size == 3);
+    bool is_double = (size == MO_64);
     TCGv_ptr fpst;
 
     if (!fp_access_check(s)) {
         return;
     }
 
-    fpst = get_fpstatus_ptr(tcg_ctx, false);
+    fpst = get_fpstatus_ptr(tcg_ctx, size == MO_16);
 
     if (is_double) {
         TCGv_i64 tcg_op = tcg_temp_new_i64(tcg_ctx);
@@ -8014,34 +8014,57 @@ static void handle_2misc_fcmp_zero(DisasContext *s, int opcode,
         bool swap = false;
         int pass, maxpasses;
 
-        switch (opcode) {
-        case 0x2e: /* FCMLT (zero) */
-            swap = true;
-            /* fall through */
-        case 0x2c: /* FCMGT (zero) */
-            genfn = gen_helper_neon_cgt_f32;
-            break;
-        case 0x2d: /* FCMEQ (zero) */
-            genfn = gen_helper_neon_ceq_f32;
-            break;
-        case 0x6d: /* FCMLE (zero) */
-            swap = true;
-            /* fall through */
-        case 0x6c: /* FCMGE (zero) */
-            genfn = gen_helper_neon_cge_f32;
-            break;
-        default:
-            g_assert_not_reached();
+        if (size == MO_16) {
+            switch (opcode) {
+            case 0x2e: /* FCMLT (zero) */
+                swap = true;
+                /* fall through */
+            case 0x2c: /* FCMGT (zero) */
+                genfn = gen_helper_advsimd_cgt_f16;
+                break;
+            case 0x2d: /* FCMEQ (zero) */
+                genfn = gen_helper_advsimd_ceq_f16;
+                break;
+            case 0x6d: /* FCMLE (zero) */
+                swap = true;
+                /* fall through */
+            case 0x6c: /* FCMGE (zero) */
+                genfn = gen_helper_advsimd_cge_f16;
+                break;
+            default:
+                g_assert_not_reached();
+            }
+        } else {
+            switch (opcode) {
+            case 0x2e: /* FCMLT (zero) */
+                swap = true;
+                /* fall through */
+            case 0x2c: /* FCMGT (zero) */
+                genfn = gen_helper_neon_cgt_f32;
+                break;
+            case 0x2d: /* FCMEQ (zero) */
+                genfn = gen_helper_neon_ceq_f32;
+                break;
+            case 0x6d: /* FCMLE (zero) */
+                swap = true;
+                /* fall through */
+            case 0x6c: /* FCMGE (zero) */
+                genfn = gen_helper_neon_cge_f32;
+                break;
+            default:
+                g_assert_not_reached();
+            }
         }
 
         if (is_scalar) {
             maxpasses = 1;
         } else {
-            maxpasses = is_q ? 4 : 2;
+            int vector_size = 8 << is_q;
+            maxpasses = vector_size >> size;
         }
 
         for (pass = 0; pass < maxpasses; pass++) {
-            read_vec_element_i32(s, tcg_op, rn, pass, MO_32);
+            read_vec_element_i32(s, tcg_op, rn, pass, size);
             if (swap) {
                 genfn(tcg_ctx, tcg_res, tcg_zero, tcg_op, fpst);
             } else {
@@ -8050,7 +8073,7 @@ static void handle_2misc_fcmp_zero(DisasContext *s, int opcode,
             if (is_scalar) {
                 write_fp_sreg(s, rd, tcg_res);
             } else {
-                write_vec_element_i32(s, tcg_res, rd, pass, MO_32);
+                write_vec_element_i32(s, tcg_res, rd, pass, size);
             }
         }
         tcg_temp_free_i32(tcg_ctx, tcg_res);
@@ -11366,7 +11389,18 @@ static void disas_simd_two_reg_misc_fp16(DisasContext *s, uint32_t insn)
     fpop = deposit32(opcode, 5, 1, a);
     fpop = deposit32(fpop, 6, 1, u);
 
+    rd = extract32(insn, 0, 5);
+    rn = extract32(insn, 5, 5);
+
     switch (fpop) {
+    break;
+    case 0x2c: /* FCMGT (zero) */
+    case 0x2d: /* FCMEQ (zero) */
+    case 0x2e: /* FCMLT (zero) */
+    case 0x6c: /* FCMGE (zero) */
+    case 0x6d: /* FCMLE (zero) */
+        handle_2misc_fcmp_zero(s, fpop, is_scalar, 0, is_q, MO_16, rn, rd);
+        return;
     case 0x18: /* FRINTN */
         need_rmode = true;
         only_in_vector = true;