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authorRichard Henderson <richard.henderson@linaro.org>2022-09-07 09:25:06 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2022-10-18 13:58:05 +0200
commitd4af67a27a817c2e96b7de176045fd95e2e9420b (patch)
tree307f7875885e577cc1bc7d7dda917f2f3788e533
parent7906847768613ea6b6e737f3295c77cdb4ff67f4 (diff)
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target/i386: Use tcg gvec ops for pmovmskb
As pmovmskb is used by strlen et al, this is the third highest overhead sse operation at %0.8. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> [Reorganize to generate code for any vector size. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--target/i386/tcg/emit.c.inc88
1 files changed, 83 insertions, 5 deletions
diff --git a/target/i386/tcg/emit.c.inc b/target/i386/tcg/emit.c.inc
index 062c92e..ad93094 100644
--- a/target/i386/tcg/emit.c.inc
+++ b/target/i386/tcg/emit.c.inc
@@ -1191,14 +1191,92 @@ static void gen_PINSR(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
gen_pinsr(s, env, decode, decode->op[2].ot);
}
+static void gen_pmovmskb_i64(TCGv_i64 d, TCGv_i64 s)
+{
+ TCGv_i64 t = tcg_temp_new_i64();
+
+ tcg_gen_andi_i64(d, s, 0x8080808080808080ull);
+
+ /*
+ * After each shift+or pair:
+ * 0: a.......b.......c.......d.......e.......f.......g.......h.......
+ * 7: ab......bc......cd......de......ef......fg......gh......h.......
+ * 14: abcd....bcde....cdef....defg....efgh....fgh.....gh......h.......
+ * 28: abcdefghbcdefgh.cdefgh..defgh...efgh....fgh.....gh......h.......
+ * The result is left in the high bits of the word.
+ */
+ tcg_gen_shli_i64(t, d, 7);
+ tcg_gen_or_i64(d, d, t);
+ tcg_gen_shli_i64(t, d, 14);
+ tcg_gen_or_i64(d, d, t);
+ tcg_gen_shli_i64(t, d, 28);
+ tcg_gen_or_i64(d, d, t);
+}
+
+static void gen_pmovmskb_vec(unsigned vece, TCGv_vec d, TCGv_vec s)
+{
+ TCGv_vec t = tcg_temp_new_vec_matching(d);
+ TCGv_vec m = tcg_constant_vec_matching(d, MO_8, 0x80);
+
+ /* See above */
+ tcg_gen_and_vec(vece, d, s, m);
+ tcg_gen_shli_vec(vece, t, d, 7);
+ tcg_gen_or_vec(vece, d, d, t);
+ tcg_gen_shli_vec(vece, t, d, 14);
+ tcg_gen_or_vec(vece, d, d, t);
+ tcg_gen_shli_vec(vece, t, d, 28);
+ tcg_gen_or_vec(vece, d, d, t);
+}
+
+#ifdef TARGET_X86_64
+#define TCG_TARGET_HAS_extract2_tl TCG_TARGET_HAS_extract2_i64
+#else
+#define TCG_TARGET_HAS_extract2_tl TCG_TARGET_HAS_extract2_i32
+#endif
+
static void gen_PMOVMSKB(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
{
- if (s->prefix & PREFIX_DATA) {
- gen_helper_pmovmskb_xmm(s->tmp2_i32, cpu_env, OP_PTR2);
- } else {
- gen_helper_pmovmskb_mmx(s->tmp2_i32, cpu_env, OP_PTR2);
+ static const TCGOpcode vecop_list[] = { INDEX_op_shli_vec, 0 };
+ static const GVecGen2 g = {
+ .fni8 = gen_pmovmskb_i64,
+ .fniv = gen_pmovmskb_vec,
+ .opt_opc = vecop_list,
+ .vece = MO_64,
+ .prefer_i64 = TCG_TARGET_REG_BITS == 64
+ };
+ MemOp ot = decode->op[2].ot;
+ int vec_len = vector_len(s, decode);
+ TCGv t = tcg_temp_new();
+
+ tcg_gen_gvec_2(offsetof(CPUX86State, xmm_t0) + xmm_offset(ot), decode->op[2].offset,
+ vec_len, vec_len, &g);
+ tcg_gen_ld8u_tl(s->T0, cpu_env, offsetof(CPUX86State, xmm_t0.ZMM_B(vec_len - 1)));
+ while (vec_len > 8) {
+ vec_len -= 8;
+ if (TCG_TARGET_HAS_extract2_tl) {
+ /*
+ * Load the next byte of the result into the high byte of T.
+ * TCG does a similar expansion of deposit to shl+extract2; by
+ * loading the whole word, the shift left is avoided.
+ */
+#ifdef TARGET_X86_64
+ tcg_gen_ld_tl(t, cpu_env, offsetof(CPUX86State, xmm_t0.ZMM_Q((vec_len - 1) / 8)));
+#else
+ tcg_gen_ld_tl(t, cpu_env, offsetof(CPUX86State, xmm_t0.ZMM_L((vec_len - 1) / 4)));
+#endif
+
+ tcg_gen_extract2_tl(s->T0, t, s->T0, TARGET_LONG_BITS - 8);
+ } else {
+ /*
+ * The _previous_ value is deposited into bits 8 and higher of t. Because
+ * those bits are known to be zero after ld8u, this becomes a shift+or
+ * if deposit is not available.
+ */
+ tcg_gen_ld8u_tl(t, cpu_env, offsetof(CPUX86State, xmm_t0.ZMM_B(vec_len - 1)));
+ tcg_gen_deposit_tl(s->T0, t, s->T0, 8, TARGET_LONG_BITS - 8);
+ }
}
- tcg_gen_extu_i32_tl(s->T0, s->tmp2_i32);
+ tcg_temp_free(t);
}
static void gen_PSHUFW(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)