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[PATCH 32/35] target/ppc: Add helper for frsqrtes
From: |
Richard Henderson |
Subject: |
[PATCH 32/35] target/ppc: Add helper for frsqrtes |
Date: |
Fri, 19 Nov 2021 17:04:59 +0100 |
There is no double-rounding bug here, because the result is
merely an estimate to within 1 part in 32, but perform the
operation with float64r32_div for consistency.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/ppc/helper.h | 1 +
target/ppc/fpu_helper.c | 19 +++++++++++++++++++
target/ppc/translate/fp-impl.c.inc | 3 +--
3 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 9810d416cf..48d12233ea 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -113,6 +113,7 @@ DEF_HELPER_2(fsqrts, f64, env, f64)
DEF_HELPER_2(fre, i64, env, i64)
DEF_HELPER_2(fres, i64, env, i64)
DEF_HELPER_2(frsqrte, i64, env, i64)
+DEF_HELPER_2(frsqrtes, i64, env, i64)
DEF_HELPER_4(fsel, i64, env, i64, i64, i64)
DEF_HELPER_FLAGS_2(ftdiv, TCG_CALL_NO_RWG_SE, i32, i64, i64)
diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index 6278d61d36..cb511f2050 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -848,6 +848,25 @@ float64 helper_frsqrte(CPUPPCState *env, float64 arg)
return retd;
}
+/* frsqrtes - frsqrtes. */
+float64 helper_frsqrtes(CPUPPCState *env, float64 arg)
+{
+ /* "Estimate" the reciprocal with actual division. */
+ float64 rets = float64_sqrt(arg, &env->fp_status);
+ float64 retd = float64r32_div(float64_one, rets, &env->fp_status);
+ int flags = get_float_exception_flags(&env->fp_status);
+
+ if (unlikely(flags & float_flag_invalid)) {
+ float_invalid_op_sqrt(env, flags, 1, GETPC());
+ }
+ if (unlikely(flags & float_flag_divbyzero)) {
+ /* Reciprocal of (square root of) zero. */
+ float_zero_divide_excp(env, GETPC());
+ }
+
+ return retd;
+}
+
/* fsel - fsel. */
uint64_t helper_fsel(CPUPPCState *env, uint64_t arg1, uint64_t arg2,
uint64_t arg3)
diff --git a/target/ppc/translate/fp-impl.c.inc
b/target/ppc/translate/fp-impl.c.inc
index 17b4d46040..9056a773cb 100644
--- a/target/ppc/translate/fp-impl.c.inc
+++ b/target/ppc/translate/fp-impl.c.inc
@@ -212,8 +212,7 @@ static void gen_frsqrtes(DisasContext *ctx)
t1 = tcg_temp_new_i64();
gen_reset_fpstatus();
get_fpr(t0, rB(ctx->opcode));
- gen_helper_frsqrte(t1, cpu_env, t0);
- gen_helper_frsp(t1, cpu_env, t1);
+ gen_helper_frsqrtes(t1, cpu_env, t0);
set_fpr(rD(ctx->opcode), t1);
gen_compute_fprf_float64(t1);
if (unlikely(Rc(ctx->opcode) != 0)) {
--
2.25.1
- [PATCH 23/35] target/ppc: Use helper_todouble in do_frsp, (continued)
- [PATCH 23/35] target/ppc: Use helper_todouble in do_frsp, Richard Henderson, 2021/11/19
- [PATCH 24/35] target/ppc: Update sqrt for new flags, Richard Henderson, 2021/11/19
- [PATCH 25/35] target/ppc: Update xsrqpi and xsrqpxp to new flags, Richard Henderson, 2021/11/19
- [PATCH 26/35] target/ppc: Update fre to new flags, Richard Henderson, 2021/11/19
- [PATCH 27/35] softfloat: Add float64r32 arithmetic routines, Richard Henderson, 2021/11/19
- [PATCH 28/35] target/ppc: Add helpers for fmadds et al, Richard Henderson, 2021/11/19
- [PATCH 29/35] target/ppc: Add helper for fsqrts, Richard Henderson, 2021/11/19
- [PATCH 30/35] target/ppc: Add helpers for fadds, fsubs, fdivs, Richard Henderson, 2021/11/19
- [PATCH 35/35] test/tcg/ppc64le: Add float reference files, Richard Henderson, 2021/11/19
- [PATCH 31/35] target/ppc: Add helper for fmuls, Richard Henderson, 2021/11/19
- [PATCH 32/35] target/ppc: Add helper for frsqrtes,
Richard Henderson <=
- [PATCH 33/35] target/ppc: Update fres to new flags and float64r32, Richard Henderson, 2021/11/19
- [PATCH 34/35] target/ppc: Use helper_todouble/tosingle in helper_xststdcsp, Richard Henderson, 2021/11/19