From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: patches@linaro.org
Subject: [Qemu-devel] [PATCH 5/5] target-arm: Implement VFPv4 fused multiply-accumulate insns
Date: Wed, 28 Sep 2011 18:27:33 +0100 [thread overview]
Message-ID: <1317230853-24970-6-git-send-email-peter.maydell@linaro.org> (raw)
In-Reply-To: <1317230853-24970-1-git-send-email-peter.maydell@linaro.org>
Implement the fused multiply-accumulate instructions (VFMA, VFMS,
VFNMA, VFNMS) which are new in VFPv4.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
target-arm/cpu.h | 1 +
target-arm/helper.c | 14 +++++++++
target-arm/helper.h | 3 ++
target-arm/translate.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 90 insertions(+), 0 deletions(-)
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index 6ab780d..e7de641 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -375,6 +375,7 @@ enum arm_features {
ARM_FEATURE_V5,
ARM_FEATURE_STRONGARM,
ARM_FEATURE_VAPA, /* cp15 VA to PA lookups */
+ ARM_FEATURE_VFP4, /* VFPv4 (implies that NEON is v2) */
};
static inline int arm_feature(CPUARMState *env, int feature)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index d3a3ba2..a1686b8 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -204,6 +204,7 @@ static void cpu_reset_model_id(CPUARMState *env, uint32_t id)
set_feature(env, ARM_FEATURE_THUMB2);
set_feature(env, ARM_FEATURE_VFP);
set_feature(env, ARM_FEATURE_VFP3);
+ set_feature(env, ARM_FEATURE_VFP4);
set_feature(env, ARM_FEATURE_VFP_FP16);
set_feature(env, ARM_FEATURE_NEON);
set_feature(env, ARM_FEATURE_THUMB2EE);
@@ -3082,6 +3083,19 @@ uint32_t HELPER(rsqrte_u32)(uint32_t a, CPUState *env)
return 0x80000000 | ((float64_val(f64) >> 21) & 0x7fffffff);
}
+/* VFPv4 fused multiply-accumulate */
+float32 VFP_HELPER(muladd, s)(float32 a, float32 b, float32 c, void *fpstp)
+{
+ float_status *fpst = fpstp;
+ return float32_muladd(a, b, c, 0, fpst);
+}
+
+float64 VFP_HELPER(muladd, d)(float64 a, float64 b, float64 c, void *fpstp)
+{
+ float_status *fpst = fpstp;
+ return float64_muladd(a, b, c, 0, fpst);
+}
+
void HELPER(set_teecr)(CPUState *env, uint32_t val)
{
val &= 1;
diff --git a/target-arm/helper.h b/target-arm/helper.h
index 3ad1cb0..16dd5fc 100644
--- a/target-arm/helper.h
+++ b/target-arm/helper.h
@@ -132,6 +132,9 @@ DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env)
DEF_HELPER_2(neon_fcvt_f16_to_f32, f32, i32, env)
DEF_HELPER_2(neon_fcvt_f32_to_f16, i32, f32, env)
+DEF_HELPER_4(vfp_muladdd, f64, f64, f64, f64, ptr)
+DEF_HELPER_4(vfp_muladds, f32, f32, f32, f32, ptr)
+
DEF_HELPER_3(recps_f32, f32, f32, f32, env)
DEF_HELPER_3(rsqrts_f32, f32, f32, f32, env)
DEF_HELPER_2(recpe_f32, f32, f32, env)
diff --git a/target-arm/translate.c b/target-arm/translate.c
index d3d7c5c..4619aa3 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -3141,6 +3141,57 @@ static int disas_vfp_insn(CPUState * env, DisasContext *s, uint32_t insn)
case 8: /* div: fn / fm */
gen_vfp_div(dp);
break;
+ case 10: /* VFNMA : fd = muladd(-fd, fn, fm) */
+ case 11: /* VFNMS : fd = muladd(-fd, -fn, fm) */
+ case 12: /* VFMA : fd = muladd( fd, fn, fm) */
+ case 13: /* VFMS : fd = muladd( fd, -fn, fm) */
+ /* These are fused multiply-add, and must be done as one
+ * floating point operation with no rounding between the
+ * multiplication and addition steps.
+ * NB that doing the negations here as separate steps is
+ * correct : an input NaN should come out with its sign bit
+ * flipped if it is a negated-input.
+ */
+ if (!arm_feature(env, ARM_FEATURE_VFP4)) {
+ return 1;
+ }
+ if (dp) {
+ TCGv_ptr fpst;
+ TCGv_i64 frd;
+ if (op & 1) {
+ /* VFNMS, VFMS */
+ gen_helper_vfp_negd(cpu_F0d, cpu_F0d);
+ }
+ frd = tcg_temp_new_i64();
+ tcg_gen_ld_f64(frd, cpu_env, vfp_reg_offset(dp, rd));
+ if (op & 2) {
+ /* VFNMA, VFNMS */
+ gen_helper_vfp_negd(frd, frd);
+ }
+ fpst = get_fpstatus_ptr(0);
+ gen_helper_vfp_muladdd(cpu_F0d, cpu_F0d,
+ cpu_F1d, frd, fpst);
+ tcg_temp_free_ptr(fpst);
+ tcg_temp_free_i64(frd);
+ } else {
+ TCGv_ptr fpst;
+ TCGv_i32 frd;
+ if (op & 1) {
+ /* VFNMS, VFMS */
+ gen_helper_vfp_negs(cpu_F0s, cpu_F0s);
+ }
+ frd = tcg_temp_new_i32();
+ tcg_gen_ld_f32(frd, cpu_env, vfp_reg_offset(dp, rd));
+ if (op & 2) {
+ gen_helper_vfp_negs(frd, frd);
+ }
+ fpst = get_fpstatus_ptr(0);
+ gen_helper_vfp_muladds(cpu_F0s, cpu_F0s,
+ cpu_F1s, frd, fpst);
+ tcg_temp_free_ptr(fpst);
+ tcg_temp_free_i32(frd);
+ }
+ break;
case 14: /* fconst */
if (!arm_feature(env, ARM_FEATURE_VFP3))
return 1;
@@ -4417,6 +4468,7 @@ static void gen_neon_narrow_op(int op, int u, int size, TCGv dest, TCGv_i64 src)
#define NEON_3R_VPMIN 21
#define NEON_3R_VQDMULH_VQRDMULH 22
#define NEON_3R_VPADD 23
+#define NEON_3R_VFM 25 /* VFMA, VFMS : float fused multiply-add */
#define NEON_3R_FLOAT_ARITH 26 /* float VADD, VSUB, VPADD, VABD */
#define NEON_3R_FLOAT_MULTIPLY 27 /* float VMLA, VMLS, VMUL */
#define NEON_3R_FLOAT_CMP 28 /* float VCEQ, VCGE, VCGT */
@@ -4449,6 +4501,7 @@ static const uint8_t neon_3r_sizes[] = {
[NEON_3R_VPMIN] = 0x7,
[NEON_3R_VQDMULH_VQRDMULH] = 0x6,
[NEON_3R_VPADD] = 0x7,
+ [NEON_3R_VFM] = 0x5, /* size bit 1 encodes op */
[NEON_3R_FLOAT_ARITH] = 0x5, /* size bit 1 encodes op */
[NEON_3R_FLOAT_MULTIPLY] = 0x5, /* size bit 1 encodes op */
[NEON_3R_FLOAT_CMP] = 0x5, /* size bit 1 encodes op */
@@ -4726,6 +4779,11 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
return 1;
}
break;
+ case NEON_3R_VFM:
+ if (!arm_feature(env, ARM_FEATURE_VFP4) || u) {
+ return 1;
+ }
+ break;
default:
break;
}
@@ -5006,6 +5064,20 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
else
gen_helper_rsqrts_f32(tmp, tmp, tmp2, cpu_env);
break;
+ case NEON_3R_VFM:
+ {
+ /* VFMA, VFMS: fused multiply-add */
+ TCGv_ptr fpstatus = get_fpstatus_ptr(1);
+ TCGv_i32 tmp3 = neon_load_reg(rd, pass);
+ if (size) {
+ /* VFMS */
+ gen_helper_vfp_negs(tmp, tmp);
+ }
+ gen_helper_vfp_muladds(tmp, tmp, tmp2, tmp3, fpstatus);
+ tcg_temp_free_i32(tmp3);
+ tcg_temp_free_ptr(fpstatus);
+ break;
+ }
default:
abort();
}
--
1.7.1
next prev parent reply other threads:[~2011-09-28 17:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-28 17:27 [Qemu-devel] [PATCH 0/5] target-arm: Implement UDIV/SDIV and fused multiply-accumulate Peter Maydell
2011-09-28 17:27 ` [Qemu-devel] [PATCH 1/5] softfloat: Reinstate accidentally disabled target-specific NaN handling Peter Maydell
2011-09-30 15:03 ` Richard Henderson
2011-09-28 17:27 ` [Qemu-devel] [PATCH 2/5] target-arm: v6 media multiply space: UNDEF on unassigned encodings Peter Maydell
2011-09-28 17:27 ` [Qemu-devel] [PATCH 3/5] target-arm: Add ARM UDIV/SDIV support Peter Maydell
2011-09-28 17:27 ` [Qemu-devel] [PATCH 4/5] softfloat: Implement fused multiply-add Peter Maydell
2011-09-30 15:28 ` Richard Henderson
2011-09-30 16:12 ` Peter Maydell
2011-09-28 17:27 ` Peter Maydell [this message]
2011-09-28 19:13 ` [Qemu-devel] [PATCH 0/5] target-arm: Implement UDIV/SDIV and fused multiply-accumulate Blue Swirl
2011-09-28 19:32 ` Peter Maydell
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1317230853-24970-6-git-send-email-peter.maydell@linaro.org \
--to=peter.maydell@linaro.org \
--cc=patches@linaro.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).