[Qemu-devel] [PATCH 3/4] target/mips: Optimize support for MSA instructions ILVL.<B|H|W|D>

[Mateja Marjanovic]

From: Mateja Marjanovic <address@hidden>

Optimize support for MSA instructions ILVL.B, ILVL.H, ILVL.W, and
ILVL.D.

Optimization is done by eliminating loops, and explicitly assigning
desired values to individual data elements. Performance measurement
is done by executing the instructions large number of times on a
computer with Intel Core i7-3770 CPU @ 3.40GHz×8.

Measured time before optimization:
  ILVL.B:  114.31 ms
  ILVL.H:   92.74 ms
  ILVL.W:  123.96 ms
  ILVL.D:   39.45 ms

Measured time after optimization:
  ILVL.B:   60.18 ms
  ILVL.H:   40.38 ms
  ILVL.W:   38.98 ms
  ILVL.D:   36.48 ms

Signed-off-by: Mateja Marjanovic <address@hidden>
---
 target/mips/msa_helper.c | 59 +++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 8 deletions(-)

diff --git a/target/mips/msa_helper.c b/target/mips/msa_helper.c
index 90ae44e..59aac72 100644
--- a/target/mips/msa_helper.c
+++ b/target/mips/msa_helper.c
@@ -1184,14 +1184,6 @@ MSA_FN_DF(pckod_df)
 
 #define MSA_DO(DF)                      \
     do {                                \
-        pwx->DF[2*i]   = L##DF(pwt, i); \
-        pwx->DF[2*i+1] = L##DF(pws, i); \
-    } while (0)
-MSA_FN_DF(ilvl_df)
-#undef MSA_DO
-
-#define MSA_DO(DF)                      \
-    do {                                \
         pwx->DF[2*i]   = R##DF(pwt, i); \
         pwx->DF[2*i+1] = R##DF(pws, i); \
     } while (0)
@@ -1318,6 +1310,57 @@ void helper_msa_ilvod_df(CPUMIPSState *env, uint32_t df, 
uint32_t wd,
     }
 }
 
+void helper_msa_ilvl_df(CPUMIPSState *env, uint32_t df, uint32_t wd,
+    uint32_t ws, uint32_t wt)
+{
+    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);
+    wr_t *pws = &(env->active_fpu.fpr[ws].wr);
+    wr_t *pwt = &(env->active_fpu.fpr[wt].wr);
+
+    switch (df) {
+    case DF_BYTE:
+        pwd->b[0]  = pwt->b[8];
+        pwd->b[1]  = pws->b[8];
+        pwd->b[2]  = pwt->b[9];
+        pwd->b[3]  = pws->b[9];
+        pwd->b[4]  = pwt->b[10];
+        pwd->b[5]  = pws->b[10];
+        pwd->b[6]  = pwt->b[11];
+        pwd->b[7]  = pws->b[11];
+        pwd->b[8]  = pwt->b[12];
+        pwd->b[9]  = pws->b[12];
+        pwd->b[10] = pwt->b[13];
+        pwd->b[11] = pws->b[13];
+        pwd->b[12] = pwt->b[14];
+        pwd->b[13] = pws->b[14];
+        pwd->b[14] = pwt->b[15];
+        pwd->b[15] = pws->b[15];
+        break;
+    case DF_HALF:
+        pwd->h[0] = pwt->h[4];
+        pwd->h[1] = pws->h[4];
+        pwd->h[2] = pwt->h[5];
+        pwd->h[3] = pws->h[5];
+        pwd->h[4] = pwt->h[6];
+        pwd->h[5] = pws->h[6];
+        pwd->h[6] = pwt->h[7];
+        pwd->h[7] = pws->h[7];
+        break;
+    case DF_WORD:
+        pwd->w[0] = pwt->w[2];
+        pwd->w[1] = pws->w[2];
+        pwd->w[2] = pwt->w[3];
+        pwd->w[3] = pws->w[3];
+        break;
+    case DF_DOUBLE:
+        pwd->d[0] = pwt->d[1];
+        pwd->d[1] = pws->d[1];
+        break;
+    default:
+        assert(0);
+    }
+}
+
 void helper_msa_sldi_df(CPUMIPSState *env, uint32_t df, uint32_t wd,
                         uint32_t ws, uint32_t n)
 {
-- 
2.7.4