target/i386: implement FMA instructions

The only issue with FMA instructions is that there are _a lot_ of them (30
opcodes, each of which comes in up to 4 versions depending on VEX.W and
VEX.L; a total of 96 possibilities).  However, they can be implement with
only 6 helpers, two for scalar operations and four for packed operations.
(Scalar versions do not do any merging; they only affect the bottom 32
or 64 bits of the output operand.  Therefore, there is no separate XMM
and YMM of the scalar helpers).

First, we can reduce the number of helpers to one third by passing four
operands (one output and three inputs); the reordering of which operands
go to the multiply and which go to the add is done in emit.c.

Second, the different instructions also dispatch to the same softfloat
function, so the flags for float32_muladd and float64_muladd are passed
in the helper as int arguments, with a little extra complication to
handle FMADDSUB and FMSUBADD.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -625,10 +625,11 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
           CPUID_EXT_SSE41 | CPUID_EXT_SSE42 | CPUID_EXT_POPCNT | \
           CPUID_EXT_XSAVE | /* CPUID_EXT_OSXSAVE is dynamic */   \
           CPUID_EXT_MOVBE | CPUID_EXT_AES | CPUID_EXT_HYPERVISOR | \
-          CPUID_EXT_RDRAND | CPUID_EXT_AVX | CPUID_EXT_F16C)
+          CPUID_EXT_RDRAND | CPUID_EXT_AVX | CPUID_EXT_F16C | \
+          CPUID_EXT_FMA)
           /* missing:
           CPUID_EXT_DTES64, CPUID_EXT_DSCPL, CPUID_EXT_VMX, CPUID_EXT_SMX,
-          CPUID_EXT_EST, CPUID_EXT_TM2, CPUID_EXT_CID, CPUID_EXT_FMA,
+          CPUID_EXT_EST, CPUID_EXT_TM2, CPUID_EXT_CID,
           CPUID_EXT_XTPR, CPUID_EXT_PDCM, CPUID_EXT_PCID, CPUID_EXT_DCA,
           CPUID_EXT_X2APIC, CPUID_EXT_TSC_DEADLINE_TIMER */
 

target/i386/ops_sse.h

@@ -2522,6 +2522,33 @@ void helper_vpermd_ymm(Reg *d, Reg *v, Reg *s)
 }
 #endif
 
+/* FMA3 op helpers */
+#if SHIFT == 1
+#define SSE_HELPER_FMAS(name, elem, F)                                         \
+    void name(CPUX86State *env, Reg *d, Reg *a, Reg *b, Reg *c, int flags)     \
+    {                                                                          \
+        d->elem(0) = F(a->elem(0), b->elem(0), c->elem(0), flags, &env->sse_status); \
+    }
+#define SSE_HELPER_FMAP(name, elem, num, F)                                    \
+    void glue(name, SUFFIX)(CPUX86State *env, Reg *d, Reg *a, Reg *b, Reg *c,  \
+                            int flags, int flip)                               \
+    {                                                                          \
+        int i;                                                                 \
+        for (i = 0; i < num; i++) {                                            \
+            d->elem(i) = F(a->elem(i), b->elem(i), c->elem(i), flags, &env->sse_status); \
+            flags ^= flip;                                                     \
+        }                                                                      \
+    }
+
+SSE_HELPER_FMAS(helper_fma4ss,  ZMM_S, float32_muladd)
+SSE_HELPER_FMAS(helper_fma4sd,  ZMM_D, float64_muladd)
+#endif
+
+#if SHIFT >= 1
+SSE_HELPER_FMAP(helper_fma4ps,  ZMM_S, 2 << SHIFT, float32_muladd)
+SSE_HELPER_FMAP(helper_fma4pd,  ZMM_D, 1 << SHIFT, float64_muladd)
+#endif
+
 #undef SSE_HELPER_S
 
 #undef LANE_WIDTH

target/i386/ops_sse_header.h

@@ -359,6 +359,17 @@ DEF_HELPER_3(glue(cvtph2ps, SUFFIX), void, env, Reg, Reg)
 DEF_HELPER_4(glue(cvtps2ph, SUFFIX), void, env, Reg, Reg, int)
 #endif
 
+/* FMA3 helpers */
+#if SHIFT == 1
+DEF_HELPER_6(fma4ss, void, env, Reg, Reg, Reg, Reg, int)
+DEF_HELPER_6(fma4sd, void, env, Reg, Reg, Reg, Reg, int)
+#endif
+
+#if SHIFT >= 1
+DEF_HELPER_7(glue(fma4ps, SUFFIX), void, env, Reg, Reg, Reg, Reg, int, int)
+DEF_HELPER_7(glue(fma4pd, SUFFIX), void, env, Reg, Reg, Reg, Reg, int, int)
+#endif
+
 /* AVX helpers */
 #if SHIFT >= 1
 DEF_HELPER_4(glue(vpermilpd, SUFFIX), void, env, Reg, Reg, Reg)

target/i386/tcg/decode-new.c.inc

@@ -376,6 +376,16 @@ static const X86OpEntry opcodes_0F38_00toEF[240] = {
     [0x92] = X86_OP_ENTRY3(VPGATHERD, V,x,  H,x,  M,d,  vex12 cpuid(AVX2) p_66), /* vgatherdps/d */
     [0x93] = X86_OP_ENTRY3(VPGATHERQ, V,x,  H,x,  M,q,  vex12 cpuid(AVX2) p_66), /* vgatherqps/d */
 
+    /* Should be exception type 2 but they do not have legacy SSE equivalents? */
+    [0x96] = X86_OP_ENTRY3(VFMADDSUB132Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x97] = X86_OP_ENTRY3(VFMSUBADD132Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
+    [0xa6] = X86_OP_ENTRY3(VFMADDSUB213Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xa7] = X86_OP_ENTRY3(VFMSUBADD213Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
+    [0xb6] = X86_OP_ENTRY3(VFMADDSUB231Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xb7] = X86_OP_ENTRY3(VFMSUBADD231Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
     [0x08] = X86_OP_ENTRY3(PSIGNB,    V,x,        H,x,  W,x,  vex4 cpuid(SSSE3) mmx avx2_256 p_00_66),
     [0x09] = X86_OP_ENTRY3(PSIGNW,    V,x,        H,x,  W,x,  vex4 cpuid(SSSE3) mmx avx2_256 p_00_66),
     [0x0a] = X86_OP_ENTRY3(PSIGND,    V,x,        H,x,  W,x,  vex4 cpuid(SSSE3) mmx avx2_256 p_00_66),
@@ -421,6 +431,34 @@ static const X86OpEntry opcodes_0F38_00toEF[240] = {
     [0x8c] = X86_OP_ENTRY3(VPMASKMOV,    V,x,  H,x, WM,x, vex6 cpuid(AVX2) p_66),
     [0x8e] = X86_OP_ENTRY3(VPMASKMOV_st, M,x,  V,x, H,x,  vex6 cpuid(AVX2) p_66),
 
+    /* Should be exception type 2 or 3 but they do not have legacy SSE equivalents? */
+    [0x98] = X86_OP_ENTRY3(VFMADD132Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x99] = X86_OP_ENTRY3(VFMADD132Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9a] = X86_OP_ENTRY3(VFMSUB132Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9b] = X86_OP_ENTRY3(VFMSUB132Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9c] = X86_OP_ENTRY3(VFNMADD132Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9d] = X86_OP_ENTRY3(VFNMADD132Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9e] = X86_OP_ENTRY3(VFNMSUB132Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0x9f] = X86_OP_ENTRY3(VFNMSUB132Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
+    [0xa8] = X86_OP_ENTRY3(VFMADD213Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xa9] = X86_OP_ENTRY3(VFMADD213Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xaa] = X86_OP_ENTRY3(VFMSUB213Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xab] = X86_OP_ENTRY3(VFMSUB213Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xac] = X86_OP_ENTRY3(VFNMADD213Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xad] = X86_OP_ENTRY3(VFNMADD213Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xae] = X86_OP_ENTRY3(VFNMSUB213Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xaf] = X86_OP_ENTRY3(VFNMSUB213Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
+    [0xb8] = X86_OP_ENTRY3(VFMADD231Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xb9] = X86_OP_ENTRY3(VFMADD231Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xba] = X86_OP_ENTRY3(VFMSUB231Px,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xbb] = X86_OP_ENTRY3(VFMSUB231Sx,  V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xbc] = X86_OP_ENTRY3(VFNMADD231Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xbd] = X86_OP_ENTRY3(VFNMADD231Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xbe] = X86_OP_ENTRY3(VFNMSUB231Px, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+    [0xbf] = X86_OP_ENTRY3(VFNMSUB231Sx, V,x,  H,x, W,x,  vex6 cpuid(FMA) p_66),
+
     [0xdb] = X86_OP_ENTRY3(VAESIMC,     V,dq, None,None, W,dq, vex4 cpuid(AES) p_66),
     [0xdc] = X86_OP_ENTRY3(VAESENC,     V,x,  H,x,       W,x,  vex4 cpuid(AES) p_66),
     [0xdd] = X86_OP_ENTRY3(VAESENCLAST, V,x,  H,x,       W,x,  vex4 cpuid(AES) p_66),
@@ -1350,6 +1388,8 @@ static bool has_cpuid_feature(DisasContext *s, X86CPUIDFeature cpuid)
         return true;
     case X86_FEAT_F16C:
         return (s->cpuid_ext_features & CPUID_EXT_F16C);
+    case X86_FEAT_FMA:
+        return (s->cpuid_ext_features & CPUID_EXT_FMA);
     case X86_FEAT_MOVBE:
         return (s->cpuid_ext_features & CPUID_EXT_MOVBE);
     case X86_FEAT_PCLMULQDQ:

target/i386/tcg/decode-new.h

@@ -105,6 +105,7 @@ typedef enum X86CPUIDFeature {
     X86_FEAT_BMI1,
     X86_FEAT_BMI2,
     X86_FEAT_F16C,
+    X86_FEAT_FMA,
     X86_FEAT_MOVBE,
     X86_FEAT_PCLMULQDQ,
     X86_FEAT_SSE,

target/i386/tcg/emit.c.inc

@@ -39,6 +39,11 @@ typedef void (*SSEFunc_0_eppt)(TCGv_ptr env, TCGv_ptr reg_a, TCGv_ptr reg_b,
                                TCGv val);
 typedef void (*SSEFunc_0_epppti)(TCGv_ptr env, TCGv_ptr reg_a, TCGv_ptr reg_b,
                                  TCGv_ptr reg_c, TCGv a0, TCGv_i32 scale);
+typedef void (*SSEFunc_0_eppppi)(TCGv_ptr env, TCGv_ptr reg_a, TCGv_ptr reg_b,
+                                  TCGv_ptr reg_c, TCGv_ptr reg_d, TCGv_i32 flags);
+typedef void (*SSEFunc_0_eppppii)(TCGv_ptr env, TCGv_ptr reg_a, TCGv_ptr reg_b,
+                                  TCGv_ptr reg_c, TCGv_ptr reg_d, TCGv_i32 even,
+                                  TCGv_i32 odd);
 
 static inline TCGv_i32 tcg_constant8u_i32(uint8_t val)
 {
@@ -491,6 +496,52 @@ FP_SSE(VMIN, min)
 FP_SSE(VDIV, div)
 FP_SSE(VMAX, max)
 
+#define FMA_SSE_PACKED(uname, ptr0, ptr1, ptr2, even, odd)                         \
+static void gen_##uname##Px(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode) \
+{                                                                                  \
+    SSEFunc_0_eppppii xmm = s->vex_w ? gen_helper_fma4pd_xmm : gen_helper_fma4ps_xmm; \
+    SSEFunc_0_eppppii ymm = s->vex_w ? gen_helper_fma4pd_ymm : gen_helper_fma4ps_ymm; \
+    SSEFunc_0_eppppii fn = s->vex_l ? ymm : xmm;                                   \
+                                                                                   \
+    fn(cpu_env, OP_PTR0, ptr0, ptr1, ptr2,                                         \
+       tcg_constant_i32(even),                                                     \
+       tcg_constant_i32((even) ^ (odd)));                                          \
+}
+
+#define FMA_SSE(uname, ptr0, ptr1, ptr2, flags)                                    \
+FMA_SSE_PACKED(uname, ptr0, ptr1, ptr2, flags, flags)                              \
+static void gen_##uname##Sx(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode) \
+{                                                                                  \
+    SSEFunc_0_eppppi fn = s->vex_w ? gen_helper_fma4sd : gen_helper_fma4ss;        \
+                                                                                   \
+    fn(cpu_env, OP_PTR0, ptr0, ptr1, ptr2,                                         \
+       tcg_constant_i32(flags));                                                   \
+}                                                                                  \
+
+FMA_SSE(VFMADD231,  OP_PTR1, OP_PTR2, OP_PTR0, 0)
+FMA_SSE(VFMADD213,  OP_PTR1, OP_PTR0, OP_PTR2, 0)
+FMA_SSE(VFMADD132,  OP_PTR0, OP_PTR2, OP_PTR1, 0)
+
+FMA_SSE(VFNMADD231, OP_PTR1, OP_PTR2, OP_PTR0, float_muladd_negate_product)
+FMA_SSE(VFNMADD213, OP_PTR1, OP_PTR0, OP_PTR2, float_muladd_negate_product)
+FMA_SSE(VFNMADD132, OP_PTR0, OP_PTR2, OP_PTR1, float_muladd_negate_product)
+
+FMA_SSE(VFMSUB231,  OP_PTR1, OP_PTR2, OP_PTR0, float_muladd_negate_c)
+FMA_SSE(VFMSUB213,  OP_PTR1, OP_PTR0, OP_PTR2, float_muladd_negate_c)
+FMA_SSE(VFMSUB132,  OP_PTR0, OP_PTR2, OP_PTR1, float_muladd_negate_c)
+
+FMA_SSE(VFNMSUB231, OP_PTR1, OP_PTR2, OP_PTR0, float_muladd_negate_c|float_muladd_negate_product)
+FMA_SSE(VFNMSUB213, OP_PTR1, OP_PTR0, OP_PTR2, float_muladd_negate_c|float_muladd_negate_product)
+FMA_SSE(VFNMSUB132, OP_PTR0, OP_PTR2, OP_PTR1, float_muladd_negate_c|float_muladd_negate_product)
+
+FMA_SSE_PACKED(VFMADDSUB231, OP_PTR1, OP_PTR2, OP_PTR0, float_muladd_negate_c, 0)
+FMA_SSE_PACKED(VFMADDSUB213, OP_PTR1, OP_PTR0, OP_PTR2, float_muladd_negate_c, 0)
+FMA_SSE_PACKED(VFMADDSUB132, OP_PTR0, OP_PTR2, OP_PTR1, float_muladd_negate_c, 0)
+
+FMA_SSE_PACKED(VFMSUBADD231, OP_PTR1, OP_PTR2, OP_PTR0, 0, float_muladd_negate_c)
+FMA_SSE_PACKED(VFMSUBADD213, OP_PTR1, OP_PTR0, OP_PTR2, 0, float_muladd_negate_c)
+FMA_SSE_PACKED(VFMSUBADD132, OP_PTR0, OP_PTR2, OP_PTR1, 0, float_muladd_negate_c)
+
 #define FP_UNPACK_SSE(uname, lname)                                                \
 static void gen_##uname(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode) \
 {                                                                                  \

target/i386/tcg/translate.c

@@ -26,6 +26,7 @@
 #include "tcg/tcg-op-gvec.h"
 #include "exec/cpu_ldst.h"
 #include "exec/translator.h"
+#include "fpu/softfloat.h"
 
 #include "exec/helper-proto.h"
 #include "exec/helper-gen.h"

tests/tcg/i386/test-avx.py

@@ -9,7 +9,7 @@ from fnmatch import fnmatch
 archs = [
     "SSE", "SSE2", "SSE3", "SSSE3", "SSE4_1", "SSE4_2",
     "AES", "AVX", "AVX2", "AES+AVX", "VAES+AVX",
-    "F16C",
+    "F16C", "FMA",
 ]
 
 ignore = set(["FISTTP",