[PULL 049/101] target/ppc: Add helpers for fadds, fsubs, fdivs

[Cédric Le Goater]

From: Richard Henderson <richard.henderson@linaro.org>

Use float64r32_{add,sub,div}.  Fixes a double-rounding issue with
performing the compuation in float64 and then rounding afterward.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211119160502.17432-31-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 target/ppc/helper.h                |  3 +++
 target/ppc/fpu_helper.c            | 40 ++++++++++++++++++++++++++++++
 target/ppc/translate/fp-impl.c.inc | 11 +++-----
 3 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 9d7c9a919a98..2b80c2f22835 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -94,9 +94,12 @@ DEF_HELPER_2(frip, i64, env, i64)
 DEF_HELPER_2(frim, i64, env, i64)
 
 DEF_HELPER_3(fadd, f64, env, f64, f64)
+DEF_HELPER_3(fadds, f64, env, f64, f64)
 DEF_HELPER_3(fsub, f64, env, f64, f64)
+DEF_HELPER_3(fsubs, f64, env, f64, f64)
 DEF_HELPER_3(fmul, f64, env, f64, f64)
 DEF_HELPER_3(fdiv, f64, env, f64, f64)
+DEF_HELPER_3(fdivs, f64, env, f64, f64)
 DEF_HELPER_4(fmadd, i64, env, i64, i64, i64)
 DEF_HELPER_4(fmsub, i64, env, i64, i64, i64)
 DEF_HELPER_4(fnmadd, i64, env, i64, i64, i64)
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index 07e1695b07b7..c36cf05d8098 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -521,6 +521,18 @@ float64 helper_fadd(CPUPPCState *env, float64 arg1, 
float64 arg2)
     return ret;
 }
 
+/* fadds - fadds. */
+float64 helper_fadds(CPUPPCState *env, float64 arg1, float64 arg2)
+{
+    float64 ret = float64r32_add(arg1, arg2, &env->fp_status);
+    int flags = get_float_exception_flags(&env->fp_status);
+
+    if (unlikely(flags & float_flag_invalid)) {
+        float_invalid_op_addsub(env, flags, 1, GETPC());
+    }
+    return ret;
+}
+
 /* fsub - fsub. */
 float64 helper_fsub(CPUPPCState *env, float64 arg1, float64 arg2)
 {
@@ -534,6 +546,18 @@ float64 helper_fsub(CPUPPCState *env, float64 arg1, 
float64 arg2)
     return ret;
 }
 
+/* fsubs - fsubs. */
+float64 helper_fsubs(CPUPPCState *env, float64 arg1, float64 arg2)
+{
+    float64 ret = float64r32_sub(arg1, arg2, &env->fp_status);
+    int flags = get_float_exception_flags(&env->fp_status);
+
+    if (unlikely(flags & float_flag_invalid)) {
+        float_invalid_op_addsub(env, flags, 1, GETPC());
+    }
+    return ret;
+}
+
 static void float_invalid_op_mul(CPUPPCState *env, int flags,
                                  bool set_fprc, uintptr_t retaddr)
 {
@@ -585,6 +609,22 @@ float64 helper_fdiv(CPUPPCState *env, float64 arg1, 
float64 arg2)
     return ret;
 }
 
+/* fdivs - fdivs. */
+float64 helper_fdivs(CPUPPCState *env, float64 arg1, float64 arg2)
+{
+    float64 ret = float64r32_div(arg1, arg2, &env->fp_status);
+    int flags = get_float_exception_flags(&env->fp_status);
+
+    if (unlikely(flags & float_flag_invalid)) {
+        float_invalid_op_div(env, flags, 1, GETPC());
+    }
+    if (unlikely(flags & float_flag_divbyzero)) {
+        float_zero_divide_excp(env, GETPC());
+    }
+
+    return ret;
+}
+
 static uint64_t float_invalid_cvt(CPUPPCState *env, int flags,
                                   uint64_t ret, uint64_t ret_nan,
                                   bool set_fprc, uintptr_t retaddr)
diff --git a/target/ppc/translate/fp-impl.c.inc 
b/target/ppc/translate/fp-impl.c.inc
index baa31d3431c7..b84097544f62 100644
--- a/target/ppc/translate/fp-impl.c.inc
+++ b/target/ppc/translate/fp-impl.c.inc
@@ -68,7 +68,7 @@ static void gen_f##name(DisasContext *ctx)                    
                \
 _GEN_FLOAT_ACB(name, 0x3F, op2, set_fprf, type);                              \
 _GEN_FLOAT_ACB(name##s, 0x3B, op2, set_fprf, type);
 
-#define _GEN_FLOAT_AB(name, op, op1, op2, inval, isfloat, set_fprf, type)     \
+#define _GEN_FLOAT_AB(name, op1, op2, inval, set_fprf, type)                  \
 static void gen_f##name(DisasContext *ctx)                                    \
 {                                                                             \
     TCGv_i64 t0;                                                              \
@@ -84,10 +84,7 @@ static void gen_f##name(DisasContext *ctx)                   
                 \
     gen_reset_fpstatus();                                                     \
     get_fpr(t0, rA(ctx->opcode));                                             \
     get_fpr(t1, rB(ctx->opcode));                                             \
-    gen_helper_f##op(t2, cpu_env, t0, t1);                                    \
-    if (isfloat) {                                                            \
-        gen_helper_frsp(t2, cpu_env, t2);                                     \
-    }                                                                         \
+    gen_helper_f##name(t2, cpu_env, t0, t1);                                  \
     set_fpr(rD(ctx->opcode), t2);                                             \
     if (set_fprf) {                                                           \
         gen_compute_fprf_float64(t2);                                         \
@@ -100,8 +97,8 @@ static void gen_f##name(DisasContext *ctx)                   
                 \
     tcg_temp_free_i64(t2);                                                    \
 }
 #define GEN_FLOAT_AB(name, op2, inval, set_fprf, type)                        \
-_GEN_FLOAT_AB(name, name, 0x3F, op2, inval, 0, set_fprf, type);               \
-_GEN_FLOAT_AB(name##s, name, 0x3B, op2, inval, 1, set_fprf, type);
+_GEN_FLOAT_AB(name, 0x3F, op2, inval, set_fprf, type);                        \
+_GEN_FLOAT_AB(name##s, 0x3B, op2, inval, set_fprf, type);
 
 #define _GEN_FLOAT_AC(name, op, op1, op2, inval, isfloat, set_fprf, type)     \
 static void gen_f##name(DisasContext *ctx)                                    \
-- 
2.31.1