From: Tom Musta <tommusta@gmail.com>
To: qemu-devel@nongnu.org
Cc: Tom Musta <tommusta@gmail.com>, qemu-ppc@nongnu.org
Subject: [Qemu-devel] [V3 PATCH 12/14] target-ppc: VSX Stage 4: Add Scalar SP Fused Multiply-Adds
Date: Tue, 3 Dec 2013 09:58:23 -0600 [thread overview]
Message-ID: <1386086305-8163-13-git-send-email-tommusta@gmail.com> (raw)
In-Reply-To: <1386086305-8163-1-git-send-email-tommusta@gmail.com>
This patch adds the Single Precision VSX Scalar Fused Multiply-Add
instructions: xsmaddasp, xsmaddmsp, xssubasp, xssubmsp, xsnmaddasp,
xsnmaddmsp, xsnmsubasp, xsnmsubmsp.
The existing VSX_MADD() macro is modified to support rounding of the
intermediate double precision result to single precision.
V2: Re-implemented per feedback from Richard Henderson. In order to
avoid double rounding and incorrect results, the operands must be
converted to true single precision values and use the single precision
fused multiply/add routine.
V3: Re-implemented per feedback from Richard Henderson. The implementation
now uses a round-to-odd algorithm to address subtle double rounding errors.
Signed-off-by: Tom Musta <tommusta@gmail.com>
---
target-ppc/fpu_helper.c | 84 ++++++++++++++++++++++++++++++----------------
target-ppc/helper.h | 8 ++++
target-ppc/translate.c | 16 +++++++++
3 files changed, 79 insertions(+), 29 deletions(-)
diff --git a/target-ppc/fpu_helper.c b/target-ppc/fpu_helper.c
index 8825db2..077d057 100644
--- a/target-ppc/fpu_helper.c
+++ b/target-ppc/fpu_helper.c
@@ -2192,7 +2192,7 @@ VSX_TSQRT(xvtsqrtsp, 4, float32, f32, -126, 23)
* afrm - A form (1=A, 0=M)
* sfprf - set FPRF
*/
-#define VSX_MADD(op, nels, tp, fld, maddflgs, afrm, sfprf) \
+#define VSX_MADD(op, nels, tp, fld, maddflgs, afrm, sfprf, r2sp) \
void helper_##op(CPUPPCState *env, uint32_t opcode) \
{ \
ppc_vsr_t xt_in, xa, xb, xt_out; \
@@ -2218,8 +2218,18 @@ void helper_##op(CPUPPCState *env, uint32_t opcode) \
for (i = 0; i < nels; i++) { \
float_status tstat = env->fp_status; \
set_float_exception_flags(0, &tstat); \
- xt_out.fld[i] = tp##_muladd(xa.fld[i], b->fld[i], c->fld[i], \
- maddflgs, &tstat); \
+ if (r2sp && (tstat.float_rounding_mode == float_round_nearest_even)) {\
+ /* Avoid double rounding errors by rounding the intermediate */ \
+ /* result to odd. */ \
+ set_float_rounding_mode(float_round_to_zero, &tstat); \
+ xt_out.fld[i] = tp##_muladd(xa.fld[i], b->fld[i], c->fld[i], \
+ maddflgs, &tstat); \
+ xt_out.fld[i] |= (get_float_exception_flags(&tstat) & \
+ float_flag_inexact) != 0; \
+ } else { \
+ xt_out.fld[i] = tp##_muladd(xa.fld[i], b->fld[i], c->fld[i], \
+ maddflgs, &tstat); \
+ } \
env->fp_status.float_exception_flags |= tstat.float_exception_flags; \
\
if (unlikely(tstat.float_exception_flags & float_flag_invalid)) { \
@@ -2242,6 +2252,13 @@ void helper_##op(CPUPPCState *env, uint32_t opcode) \
fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXISI, sfprf); \
} \
} \
+ \
+ if (r2sp) { \
+ float32 tmp32 = float64_to_float32(xt_out.fld[i], \
+ &env->fp_status); \
+ xt_out.fld[i] = float32_to_float64(tmp32, &env->fp_status); \
+ } \
+ \
if (sfprf) { \
helper_compute_fprf(env, xt_out.fld[i], sfprf); \
} \
@@ -2255,32 +2272,41 @@ void helper_##op(CPUPPCState *env, uint32_t opcode) \
#define NMADD_FLGS float_muladd_negate_result
#define NMSUB_FLGS (float_muladd_negate_c | float_muladd_negate_result)
-VSX_MADD(xsmaddadp, 1, float64, f64, MADD_FLGS, 1, 1)
-VSX_MADD(xsmaddmdp, 1, float64, f64, MADD_FLGS, 0, 1)
-VSX_MADD(xsmsubadp, 1, float64, f64, MSUB_FLGS, 1, 1)
-VSX_MADD(xsmsubmdp, 1, float64, f64, MSUB_FLGS, 0, 1)
-VSX_MADD(xsnmaddadp, 1, float64, f64, NMADD_FLGS, 1, 1)
-VSX_MADD(xsnmaddmdp, 1, float64, f64, NMADD_FLGS, 0, 1)
-VSX_MADD(xsnmsubadp, 1, float64, f64, NMSUB_FLGS, 1, 1)
-VSX_MADD(xsnmsubmdp, 1, float64, f64, NMSUB_FLGS, 0, 1)
-
-VSX_MADD(xvmaddadp, 2, float64, f64, MADD_FLGS, 1, 0)
-VSX_MADD(xvmaddmdp, 2, float64, f64, MADD_FLGS, 0, 0)
-VSX_MADD(xvmsubadp, 2, float64, f64, MSUB_FLGS, 1, 0)
-VSX_MADD(xvmsubmdp, 2, float64, f64, MSUB_FLGS, 0, 0)
-VSX_MADD(xvnmaddadp, 2, float64, f64, NMADD_FLGS, 1, 0)
-VSX_MADD(xvnmaddmdp, 2, float64, f64, NMADD_FLGS, 0, 0)
-VSX_MADD(xvnmsubadp, 2, float64, f64, NMSUB_FLGS, 1, 0)
-VSX_MADD(xvnmsubmdp, 2, float64, f64, NMSUB_FLGS, 0, 0)
-
-VSX_MADD(xvmaddasp, 4, float32, f32, MADD_FLGS, 1, 0)
-VSX_MADD(xvmaddmsp, 4, float32, f32, MADD_FLGS, 0, 0)
-VSX_MADD(xvmsubasp, 4, float32, f32, MSUB_FLGS, 1, 0)
-VSX_MADD(xvmsubmsp, 4, float32, f32, MSUB_FLGS, 0, 0)
-VSX_MADD(xvnmaddasp, 4, float32, f32, NMADD_FLGS, 1, 0)
-VSX_MADD(xvnmaddmsp, 4, float32, f32, NMADD_FLGS, 0, 0)
-VSX_MADD(xvnmsubasp, 4, float32, f32, NMSUB_FLGS, 1, 0)
-VSX_MADD(xvnmsubmsp, 4, float32, f32, NMSUB_FLGS, 0, 0)
+VSX_MADD(xsmaddadp, 1, float64, f64, MADD_FLGS, 1, 1, 0)
+VSX_MADD(xsmaddmdp, 1, float64, f64, MADD_FLGS, 0, 1, 0)
+VSX_MADD(xsmsubadp, 1, float64, f64, MSUB_FLGS, 1, 1, 0)
+VSX_MADD(xsmsubmdp, 1, float64, f64, MSUB_FLGS, 0, 1, 0)
+VSX_MADD(xsnmaddadp, 1, float64, f64, NMADD_FLGS, 1, 1, 0)
+VSX_MADD(xsnmaddmdp, 1, float64, f64, NMADD_FLGS, 0, 1, 0)
+VSX_MADD(xsnmsubadp, 1, float64, f64, NMSUB_FLGS, 1, 1, 0)
+VSX_MADD(xsnmsubmdp, 1, float64, f64, NMSUB_FLGS, 0, 1, 0)
+
+VSX_MADD(xsmaddasp, 1, float64, f64, MADD_FLGS, 1, 1, 1)
+VSX_MADD(xsmaddmsp, 1, float64, f64, MADD_FLGS, 0, 1, 1)
+VSX_MADD(xsmsubasp, 1, float64, f64, MSUB_FLGS, 1, 1, 1)
+VSX_MADD(xsmsubmsp, 1, float64, f64, MSUB_FLGS, 0, 1, 1)
+VSX_MADD(xsnmaddasp, 1, float64, f64, NMADD_FLGS, 1, 1, 1)
+VSX_MADD(xsnmaddmsp, 1, float64, f64, NMADD_FLGS, 0, 1, 1)
+VSX_MADD(xsnmsubasp, 1, float64, f64, NMSUB_FLGS, 1, 1, 1)
+VSX_MADD(xsnmsubmsp, 1, float64, f64, NMSUB_FLGS, 0, 1, 1)
+
+VSX_MADD(xvmaddadp, 2, float64, f64, MADD_FLGS, 1, 0, 0)
+VSX_MADD(xvmaddmdp, 2, float64, f64, MADD_FLGS, 0, 0, 0)
+VSX_MADD(xvmsubadp, 2, float64, f64, MSUB_FLGS, 1, 0, 0)
+VSX_MADD(xvmsubmdp, 2, float64, f64, MSUB_FLGS, 0, 0, 0)
+VSX_MADD(xvnmaddadp, 2, float64, f64, NMADD_FLGS, 1, 0, 0)
+VSX_MADD(xvnmaddmdp, 2, float64, f64, NMADD_FLGS, 0, 0, 0)
+VSX_MADD(xvnmsubadp, 2, float64, f64, NMSUB_FLGS, 1, 0, 0)
+VSX_MADD(xvnmsubmdp, 2, float64, f64, NMSUB_FLGS, 0, 0, 0)
+
+VSX_MADD(xvmaddasp, 4, float32, f32, MADD_FLGS, 1, 0, 0)
+VSX_MADD(xvmaddmsp, 4, float32, f32, MADD_FLGS, 0, 0, 0)
+VSX_MADD(xvmsubasp, 4, float32, f32, MSUB_FLGS, 1, 0, 0)
+VSX_MADD(xvmsubmsp, 4, float32, f32, MSUB_FLGS, 0, 0, 0)
+VSX_MADD(xvnmaddasp, 4, float32, f32, NMADD_FLGS, 1, 0, 0)
+VSX_MADD(xvnmaddmsp, 4, float32, f32, NMADD_FLGS, 0, 0, 0)
+VSX_MADD(xvnmsubasp, 4, float32, f32, NMSUB_FLGS, 1, 0, 0)
+VSX_MADD(xvnmsubmsp, 4, float32, f32, NMSUB_FLGS, 0, 0, 0)
#define VSX_SCALAR_CMP(op, ordered) \
void helper_##op(CPUPPCState *env, uint32_t opcode) \
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 84c6ee1..655b670 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -293,6 +293,14 @@ DEF_HELPER_2(xsdivsp, void, env, i32)
DEF_HELPER_2(xsresp, void, env, i32)
DEF_HELPER_2(xssqrtsp, void, env, i32)
DEF_HELPER_2(xsrsqrtesp, void, env, i32)
+DEF_HELPER_2(xsmaddasp, void, env, i32)
+DEF_HELPER_2(xsmaddmsp, void, env, i32)
+DEF_HELPER_2(xsmsubasp, void, env, i32)
+DEF_HELPER_2(xsmsubmsp, void, env, i32)
+DEF_HELPER_2(xsnmaddasp, void, env, i32)
+DEF_HELPER_2(xsnmaddmsp, void, env, i32)
+DEF_HELPER_2(xsnmsubasp, void, env, i32)
+DEF_HELPER_2(xsnmsubmsp, void, env, i32)
DEF_HELPER_2(xvadddp, void, env, i32)
DEF_HELPER_2(xvsubdp, void, env, i32)
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index ae80289..672cf0a 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -7348,6 +7348,14 @@ GEN_VSX_HELPER_2(xsdivsp, 0x00, 0x03, 0, PPC2_VSX207)
GEN_VSX_HELPER_2(xsresp, 0x14, 0x01, 0, PPC2_VSX207)
GEN_VSX_HELPER_2(xssqrtsp, 0x16, 0x00, 0, PPC2_VSX207)
GEN_VSX_HELPER_2(xsrsqrtesp, 0x14, 0x00, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsmaddasp, 0x04, 0x00, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsmaddmsp, 0x04, 0x01, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsmsubasp, 0x04, 0x02, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsmsubmsp, 0x04, 0x03, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsnmaddasp, 0x04, 0x10, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsnmaddmsp, 0x04, 0x11, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsnmsubasp, 0x04, 0x12, 0, PPC2_VSX207)
+GEN_VSX_HELPER_2(xsnmsubmsp, 0x04, 0x13, 0, PPC2_VSX207)
GEN_VSX_HELPER_2(xvadddp, 0x00, 0x0C, 0, PPC2_VSX)
GEN_VSX_HELPER_2(xvsubdp, 0x00, 0x0D, 0, PPC2_VSX)
@@ -10163,6 +10171,14 @@ GEN_XX3FORM(xsdivsp, 0x00, 0x03, PPC2_VSX207),
GEN_XX2FORM(xsresp, 0x14, 0x01, PPC2_VSX207),
GEN_XX2FORM(xssqrtsp, 0x16, 0x00, PPC2_VSX207),
GEN_XX2FORM(xsrsqrtesp, 0x14, 0x00, PPC2_VSX207),
+GEN_XX3FORM(xsmaddasp, 0x04, 0x00, PPC2_VSX207),
+GEN_XX3FORM(xsmaddmsp, 0x04, 0x01, PPC2_VSX207),
+GEN_XX3FORM(xsmsubasp, 0x04, 0x02, PPC2_VSX207),
+GEN_XX3FORM(xsmsubmsp, 0x04, 0x03, PPC2_VSX207),
+GEN_XX3FORM(xsnmaddasp, 0x04, 0x10, PPC2_VSX207),
+GEN_XX3FORM(xsnmaddmsp, 0x04, 0x11, PPC2_VSX207),
+GEN_XX3FORM(xsnmsubasp, 0x04, 0x12, PPC2_VSX207),
+GEN_XX3FORM(xsnmsubmsp, 0x04, 0x13, PPC2_VSX207),
GEN_XX3FORM(xvadddp, 0x00, 0x0C, PPC2_VSX),
GEN_XX3FORM(xvsubdp, 0x00, 0x0D, PPC2_VSX),
--
1.7.1
next prev parent reply other threads:[~2013-12-03 15:59 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-03 15:58 [Qemu-devel] [V3 PATCH 00/14] target-ppc: VSX Stage 4 Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 01/14] target-ppc: VSX Stage 4: Add VSX 2.07 Flag Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 02/14] target-ppc: VSX Stage 4: Refactor lxsdx Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 03/14] target-ppc: VSX Stage 4: Add lxsiwax, lxsiwzx and lxsspx Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 04/14] target-ppc: VSX Stage 4: Refactor stxsdx Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 05/14] target-ppc: VSX Stage 4: Add stxsiwx and stxsspx Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 06/14] target-ppc: VSX Stage 4: Add xsaddsp and xssubsp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 07/14] target-ppc: VSX Stage 4: Add xsmulsp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 08/14] target-ppc: VSX Stage 4: Add xsdivsp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 09/14] target-ppc: VSX Stage 4: Add xsresp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 10/14] target-ppc: VSX Stage 4: Add xssqrtsp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 11/14] target-ppc: VSX Stage 4: add xsrsqrtesp Tom Musta
2013-12-03 15:58 ` Tom Musta [this message]
2013-12-04 0:23 ` [Qemu-devel] [V3 PATCH 12/14] target-ppc: VSX Stage 4: Add Scalar SP Fused Multiply-Adds Richard Henderson
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 13/14] target-ppc: VSX Stage 4: Add xscvsxdsp and xscvuxdsp Tom Musta
2013-12-03 15:58 ` [Qemu-devel] [V3 PATCH 14/14] target-ppc: VSX Stage 4: Add xxleqv, xxlnand and xxlorc Tom Musta
2013-12-04 0:25 ` [Qemu-devel] [V3 PATCH 00/14] target-ppc: VSX Stage 4 Richard Henderson
2013-12-04 18:13 ` Tom Musta
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