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[PULL,03/38] target/arm: Use cmpsel in gen_ushl_vec

Message ID 20240919131106.3362543-4-peter.maydell@linaro.org
State New
Headers show
Series [PULL,01/38] target/arm: Replace tcg_gen_dupi_vec with constants in gengvec.c | expand

Commit Message

Peter Maydell Sept. 19, 2024, 1:10 p.m. UTC 
From: Richard Henderson <richard.henderson@linaro.org>

Instead of cmp+and or cmp+andc, use cmpsel.  This will
be better for hosts that use predicate registers for cmp.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240912024114.1097832-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/gengvec.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)
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Patch

diff --git a/target/arm/tcg/gengvec.c b/target/arm/tcg/gengvec.c
index 726a1383aed..3edbf3a2627 100644
--- a/target/arm/tcg/gengvec.c
+++ b/target/arm/tcg/gengvec.c
@@ -1041,7 +1041,7 @@  static void gen_ushl_vec(unsigned vece, TCGv_vec dst,
     TCGv_vec rval = tcg_temp_new_vec_matching(dst);
     TCGv_vec lsh = tcg_temp_new_vec_matching(dst);
     TCGv_vec rsh = tcg_temp_new_vec_matching(dst);
-    TCGv_vec max;
+    TCGv_vec max, zero;
 
     tcg_gen_neg_vec(vece, rsh, shift);
     if (vece == MO_8) {
@@ -1061,23 +1061,20 @@  static void gen_ushl_vec(unsigned vece, TCGv_vec dst,
     tcg_gen_shrv_vec(vece, rval, src, rsh);
 
     /*
-     * The choice of LT (signed) and GEU (unsigned) are biased toward
+     * The choice of GE (signed) and GEU (unsigned) are biased toward
      * the instructions of the x86_64 host.  For MO_8, the whole byte
      * is significant so we must use an unsigned compare; otherwise we
      * have already masked to a byte and so a signed compare works.
      * Other tcg hosts have a full set of comparisons and do not care.
      */
+    zero = tcg_constant_vec_matching(dst, vece, 0);
     max = tcg_constant_vec_matching(dst, vece, 8 << vece);
     if (vece == MO_8) {
-        tcg_gen_cmp_vec(TCG_COND_GEU, vece, lsh, lsh, max);
-        tcg_gen_cmp_vec(TCG_COND_GEU, vece, rsh, rsh, max);
-        tcg_gen_andc_vec(vece, lval, lval, lsh);
-        tcg_gen_andc_vec(vece, rval, rval, rsh);
+        tcg_gen_cmpsel_vec(TCG_COND_GEU, vece, lval, lsh, max, zero, lval);
+        tcg_gen_cmpsel_vec(TCG_COND_GEU, vece, rval, rsh, max, zero, rval);
     } else {
-        tcg_gen_cmp_vec(TCG_COND_LT, vece, lsh, lsh, max);
-        tcg_gen_cmp_vec(TCG_COND_LT, vece, rsh, rsh, max);
-        tcg_gen_and_vec(vece, lval, lval, lsh);
-        tcg_gen_and_vec(vece, rval, rval, rsh);
+        tcg_gen_cmpsel_vec(TCG_COND_GE, vece, lval, lsh, max, zero, lval);
+        tcg_gen_cmpsel_vec(TCG_COND_GE, vece, rval, rsh, max, zero, rval);
     }
     tcg_gen_or_vec(vece, dst, lval, rval);
 }
@@ -1087,7 +1084,7 @@  void gen_gvec_ushl(unsigned vece, uint32_t rd_ofs, uint32_t rn_ofs,
 {
     static const TCGOpcode vecop_list[] = {
         INDEX_op_neg_vec, INDEX_op_shlv_vec,
-        INDEX_op_shrv_vec, INDEX_op_cmp_vec, 0
+        INDEX_op_shrv_vec, INDEX_op_cmpsel_vec, 0
     };
     static const GVecGen3 ops[4] = {
         { .fniv = gen_ushl_vec,