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.
Signed-off-by: Tom Musta <tommu...@gmail.com>
---
target-ppc/fpu_helper.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++
target-ppc/helper.h | 8 +++++
target-ppc/translate.c | 16 ++++++++++
3 files changed, 101 insertions(+), 0 deletions(-)
diff --git a/target-ppc/fpu_helper.c b/target-ppc/fpu_helper.c
index 8825db2..6428c54 100644
--- a/target-ppc/fpu_helper.c
+++ b/target-ppc/fpu_helper.c
@@ -2250,6 +2250,74 @@ void helper_##op(CPUPPCState *env, uint32_t opcode)
\
helper_float_check_status(env); \
}
+/* VSX_XSMADDSP - VSX scalar muliply/add single precision variations
+ * op - instruction mnemonic
+ * maddflgs - flags for the float*muladd routine that control the
+ * various forms (madd, msub, nmadd, nmsub)
+ * afrm - A form (1=A, 0=M)
+ */
+#define VSX_XSMADDSP(op, maddflgs, afrm) \
+void helper_##op(CPUPPCState *env, uint32_t opcode) \
+{ \
+ ppc_vsr_t xt_in, xa, xb, xt_out; \
+ ppc_vsr_t *b, *c; \
+ \
+ if (afrm) { /* AxB + T */ \
+ b = &xb; \
+ c = &xt_in; \
+ } else { /* AxT + B */ \
+ b = &xt_in; \
+ c = &xb; \
+ } \
+ \
+ getVSR(xA(opcode), &xa, env); \
+ getVSR(xB(opcode), &xb, env); \
+ getVSR(xT(opcode), &xt_in, env); \
+ \
+ xt_out = xt_in; \
+ \
+ helper_reset_fpstatus(env); \
+ \
+ /* NOTE: in order to get accurate results, we must first round back */ \
+ /* to single precision and use the fused multiply add routine */ \
+ /* for 32-bit floats. */ \
+ float_status tstat = env->fp_status; \
+ float32 a32 = float64_to_float32(xa.f64[0], &tstat); \
+ float32 b32 = float64_to_float32(b->f64[0], &tstat); \
+ float32 c32 = float64_to_float32(c->f64[0], &tstat); \
+ \
+ set_float_exception_flags(0, &tstat); \
+ float32 t32 = float32_muladd(a32, b32, c32, maddflgs, &tstat); \
+ \
+ env->fp_status.float_exception_flags |= tstat.float_exception_flags; \
+ \
+ if (unlikely(tstat.float_exception_flags & float_flag_invalid)) { \
+ if (float64_is_signaling_nan(xa.f64[0]) || \
+ float64_is_signaling_nan(b->f64[0]) || \
+ float64_is_signaling_nan(c->f64[0])) { \
+ fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSNAN, 1); \
+ tstat.float_exception_flags &= ~float_flag_invalid; \
+ } \
+ if ((float64_is_infinity(xa.f64[0]) && float64_is_zero(b->f64[0])) || \
+ (float64_is_zero(xa.f64[0]) && float64_is_infinity(b->f64[0]))) { \
+ xt_out.f64[0] = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXIMZ, \
+ 1); \
+ tstat.float_exception_flags &= ~float_flag_invalid; \
+ } \
+ if ((tstat.float_exception_flags & float_flag_invalid) && \
+ ((float64_is_infinity(xa.f64[0]) || \
+ float64_is_infinity(b->f64[0])) && \
+ float64_is_infinity(c->f64[0]))) { \
+ fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXISI, 1); \
+ } \
+ } \
+ \
+ xt_out.f64[0] = float32_to_float64(t32, &tstat); \
+ helper_compute_fprf(env, xt_out.f64[0], 1); \
+ putVSR(xT(opcode), &xt_out, env); \
+ helper_float_check_status(env); \
+}
+
#define MADD_FLGS 0
#define MSUB_FLGS float_muladd_negate_c
#define NMADD_FLGS float_muladd_negate_result
@@ -2264,6 +2332,15 @@ 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_XSMADDSP(xsmaddasp, MADD_FLGS, 1)
+VSX_XSMADDSP(xsmaddmsp, MADD_FLGS, 0)
+VSX_XSMADDSP(xsmsubasp, MSUB_FLGS, 1)
+VSX_XSMADDSP(xsmsubmsp, MSUB_FLGS, 0)
+VSX_XSMADDSP(xsnmaddasp, NMADD_FLGS, 1)
+VSX_XSMADDSP(xsnmaddmsp, NMADD_FLGS, 0)
+VSX_XSMADDSP(xsnmsubasp, NMSUB_FLGS, 1)
+VSX_XSMADDSP(xsnmsubmsp, NMSUB_FLGS, 0)
+
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)
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
