diff mbox

[2/4] target-tricore: Added MADD.F and MSUB.F instructions

Message ID 1464562768-8954-3-git-send-email-peer.adelt@c-lab.de
State New
Headers show

Commit Message

Peer Adelt May 29, 2016, 10:59 p.m. UTC 
From: Peer Adelt <peer.adelt@c-lab.de>

Multiplies D[a] and D[b] and adds/subtracts the result to/from D[d].
The result is put in D[c]. All operands are floating-point numbers.

Signed-off-by: Peer Adelt <peer.adelt@c-lab.de>
---
 target-tricore/fpu_helper.c | 54 +++++++++++++++++++++++++++++++++++++++++++++
 target-tricore/helper.h     |  2 ++
 target-tricore/translate.c  |  8 +++++++
 3 files changed, 64 insertions(+)

Comments

Bastian Koppelmann May 31, 2016, 11:13 a.m. UTC | #1 
On 05/30/2016 12:59 AM, peer.adelt@c-lab.de wrote:
> +uint32_t helper_fmadd(CPUTriCoreState *env, uint32_t r1,
> +                      uint32_t r2, uint32_t r3)
> +{
> +    uint32_t flags;
> +    float32 arg1 = make_float32(r1);
> +    float32 arg2 = make_float32(r2);
> +    float32 arg3 = make_float32(r3);
> +    float32 f_result;
> +
> +    flags = f_get_excp_flags(env);
> +    f_result = float32_muladd(arg1, arg2, arg3, flags, &env->fp_status);
The flags argument allows the caller to select negation of the
addend, the intermediate product, or the final result. These are not
excp_flags. Additionally, you need to collect the excp_flags after doing
the muladd.
> +
> +    if (flags) {
> +        /* If the output is a NaN, but the inputs aren't,
> +           we return a unique value.  */
> +        if ((flags & float_flag_invalid)
> +            && !float32_is_any_nan(arg1)
> +            && !float32_is_any_nan(arg2)) {
You are not doing what the comment says. You have three inputs here but
you only check two.

> +    float32 arg2 = make_float32(r2);
> +    float32 arg3 = make_float32(r3);
> +    float32 f_result;
> +
> +    flags = f_get_excp_flags(env);
> +    f_result = float32_muladd(-arg1, arg2, arg3, flags, &env->fp_status);
Likewise.

> +    if (flags) {
> +        /* If the output is a NaN, but the inputs aren't,
> +           we return a unique value.  */
> +        if ((flags & float_flag_invalid)
> +            && !float32_is_any_nan(arg1)
> +            && !float32_is_any_nan(arg2)) {
Likewise.

Cheers,
    Bastian
Richard Henderson June 4, 2016, 4:55 p.m. UTC | #2 
On 05/29/2016 03:59 PM, peer.adelt@c-lab.de wrote:
> +    flags = f_get_excp_flags(env);
> +    f_result = float32_muladd(-arg1, arg2, arg3, flags, &env->fp_status);

Bastian already pointed out that flags here is being used wrong,
but I thought I'd reinforce that "-arg1" is not how floating-point
negation works.  You need to use float_muladd_negate_product as
that 4th argument to float32_muladd.


r~
diff mbox

Patch

diff --git a/target-tricore/fpu_helper.c b/target-tricore/fpu_helper.c
index ccaa6b0..3207818 100644
--- a/target-tricore/fpu_helper.c
+++ b/target-tricore/fpu_helper.c
@@ -159,6 +159,60 @@  uint32_t helper_fdiv(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
     return (uint32_t)f_result;
 }
 
+uint32_t helper_fmadd(CPUTriCoreState *env, uint32_t r1,
+                      uint32_t r2, uint32_t r3)
+{
+    uint32_t flags;
+    float32 arg1 = make_float32(r1);
+    float32 arg2 = make_float32(r2);
+    float32 arg3 = make_float32(r3);
+    float32 f_result;
+
+    flags = f_get_excp_flags(env);
+    f_result = float32_muladd(arg1, arg2, arg3, flags, &env->fp_status);
+
+    if (flags) {
+        /* If the output is a NaN, but the inputs aren't,
+           we return a unique value.  */
+        if ((flags & float_flag_invalid)
+            && !float32_is_any_nan(arg1)
+            && !float32_is_any_nan(arg2)) {
+                f_result = MUL_NAN;
+        }
+        f_update_psw_flags(env, flags);
+    } else {
+        env->FPU_FS = 0;
+    }
+    return (uint32_t)f_result;
+}
+
+uint32_t helper_fmsub(CPUTriCoreState *env, uint32_t r1,
+                      uint32_t r2, uint32_t r3)
+{
+    uint32_t flags;
+    float32 arg1 = make_float32(r1);
+    float32 arg2 = make_float32(r2);
+    float32 arg3 = make_float32(r3);
+    float32 f_result;
+
+    flags = f_get_excp_flags(env);
+    f_result = float32_muladd(-arg1, arg2, arg3, flags, &env->fp_status);
+
+    if (flags) {
+        /* If the output is a NaN, but the inputs aren't,
+           we return a unique value.  */
+        if ((flags & float_flag_invalid)
+            && !float32_is_any_nan(arg1)
+            && !float32_is_any_nan(arg2)) {
+                f_result = MUL_NAN;
+        }
+        f_update_psw_flags(env, flags);
+    } else {
+        env->FPU_FS = 0;
+    }
+    return (uint32_t)f_result;
+}
+
 uint32_t helper_fcmp(CPUTriCoreState *env, uint32_t r1, uint32_t r2)
 {
     uint32_t result, flags;
diff --git a/target-tricore/helper.h b/target-tricore/helper.h
index 467c880..c897a44 100644
--- a/target-tricore/helper.h
+++ b/target-tricore/helper.h
@@ -109,6 +109,8 @@  DEF_HELPER_3(fadd, i32, env, i32, i32)
 DEF_HELPER_3(fsub, i32, env, i32, i32)
 DEF_HELPER_3(fmul, i32, env, i32, i32)
 DEF_HELPER_3(fdiv, i32, env, i32, i32)
+DEF_HELPER_4(fmadd, i32, env, i32, i32, i32)
+DEF_HELPER_4(fmsub, i32, env, i32, i32, i32)
 DEF_HELPER_3(fcmp, i32, env, i32, i32)
 DEF_HELPER_2(ftoi, i32, env, i32)
 DEF_HELPER_2(itof, i32, env, i32)
diff --git a/target-tricore/translate.c b/target-tricore/translate.c
index a109c15..e66b433 100644
--- a/target-tricore/translate.c
+++ b/target-tricore/translate.c
@@ -7096,6 +7096,14 @@  static void decode_rrr_divide(CPUTriCoreState *env, DisasContext *ctx)
     case OPC2_32_RRR_SUB_F:
         gen_helper_fsub(cpu_gpr_d[r4], cpu_env, cpu_gpr_d[r1], cpu_gpr_d[r3]);
         break;
+    case OPC2_32_RRR_MADD_F:
+        gen_helper_fmadd(cpu_gpr_d[r4], cpu_env, cpu_gpr_d[r1],
+                         cpu_gpr_d[r2], cpu_gpr_d[r3]);
+        break;
+    case OPC2_32_RRR_MSUB_F:
+        gen_helper_fmsub(cpu_gpr_d[r4], cpu_env, cpu_gpr_d[r1],
+                         cpu_gpr_d[r2], cpu_gpr_d[r3]);
+        break;
     default:
         generate_trap(ctx, TRAPC_INSN_ERR, TIN2_IOPC);
     }