[v5,6/8] target/ppc: Optimize emulation of vclzw instruction
diff mbox series

Message ID 1563200574-11098-7-git-send-email-stefan.brankovic@rt-rk.com
State New
Headers show
Series
  • target/ppc: Optimize emulation of some Altivec instructions
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Commit Message

Stefan Brankovic July 15, 2019, 2:22 p.m. UTC
Optimize Altivec instruction vclzw (Vector Count Leading Zeros Word).
This instruction counts the number of leading zeros of each word element
in source register and places result in the appropriate word element of
destination register.

Counting is to be performed in four iterations of for loop(one for each
word elemnt of source register vB). Every iteration consists of loading
appropriate word element from source register, counting leading zeros
with tcg_gen_clzi_i32, and saving the result in appropriate word element
of destination register.

Signed-off-by: Stefan Brankovic <stefan.brankovic@rt-rk.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/ppc/helper.h                 |  1 -
 target/ppc/int_helper.c             |  3 ---
 target/ppc/translate/vmx-impl.inc.c | 28 +++++++++++++++++++++++++++-
 3 files changed, 27 insertions(+), 5 deletions(-)

Patch
diff mbox series

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 3b92e3b..595241c 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -305,7 +305,6 @@  DEF_HELPER_4(vctsxs, void, env, avr, avr, i32)
 
 DEF_HELPER_2(vclzb, void, avr, avr)
 DEF_HELPER_2(vclzh, void, avr, avr)
-DEF_HELPER_2(vclzw, void, avr, avr)
 DEF_HELPER_2(vctzb, void, avr, avr)
 DEF_HELPER_2(vctzh, void, avr, avr)
 DEF_HELPER_2(vctzw, void, avr, avr)
diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c
index 3134798..82cb12e 100644
--- a/target/ppc/int_helper.c
+++ b/target/ppc/int_helper.c
@@ -1802,15 +1802,12 @@  VUPK(lsw, s64, s32, UPKLO)
 
 #define clzb(v) ((v) ? clz32((uint32_t)(v) << 24) : 8)
 #define clzh(v) ((v) ? clz32((uint32_t)(v) << 16) : 16)
-#define clzw(v) clz32((v))
 
 VGENERIC_DO(clzb, u8)
 VGENERIC_DO(clzh, u16)
-VGENERIC_DO(clzw, u32)
 
 #undef clzb
 #undef clzh
-#undef clzw
 
 #define ctzb(v) ((v) ? ctz32(v) : 8)
 #define ctzh(v) ((v) ? ctz32(v) : 16)
diff --git a/target/ppc/translate/vmx-impl.inc.c b/target/ppc/translate/vmx-impl.inc.c
index 75c5c8c..456666a 100644
--- a/target/ppc/translate/vmx-impl.inc.c
+++ b/target/ppc/translate/vmx-impl.inc.c
@@ -840,6 +840,32 @@  static void trans_vgbbd(DisasContext *ctx)
 }
 
 /*
+ * vclzw VRT,VRB - Vector Count Leading Zeros Word
+ *
+ * Counting the number of leading zero bits of each word element in source
+ * register and placing result in appropriate word element of destination
+ * register.
+ */
+static void trans_vclzw(DisasContext *ctx)
+{
+    int VT = rD(ctx->opcode);
+    int VB = rB(ctx->opcode);
+    TCGv_i32 tmp = tcg_temp_new_i32();
+    int i;
+
+    /* Perform count for every word element using tcg_gen_clzi_i32. */
+    for (i = 0; i < 4; i++) {
+        tcg_gen_ld_i32(tmp, cpu_env,
+            offsetof(CPUPPCState, vsr[32 + VB].u64[0]) + i * 4);
+        tcg_gen_clzi_i32(tmp, tmp, 32);
+        tcg_gen_st_i32(tmp, cpu_env,
+            offsetof(CPUPPCState, vsr[32 + VT].u64[0]) + i * 4);
+    }
+
+    tcg_temp_free_i32(tmp);
+}
+
+/*
  * vclzd VRT,VRB - Vector Count Leading Zeros Doubleword
  *
  * Counting the number of leading zero bits of each doubleword element in source
@@ -1380,7 +1406,7 @@  GEN_VAFORM_PAIRED(vmaddfp, vnmsubfp, 23)
 
 GEN_VXFORM_NOA(vclzb, 1, 28)
 GEN_VXFORM_NOA(vclzh, 1, 29)
-GEN_VXFORM_NOA(vclzw, 1, 30)
+GEN_VXFORM_TRANS(vclzw, 1, 30)
 GEN_VXFORM_TRANS(vclzd, 1, 31)
 GEN_VXFORM_NOA_2(vnegw, 1, 24, 6)
 GEN_VXFORM_NOA_2(vnegd, 1, 24, 7)