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authorRichard Henderson <rth@twiddle.net>2017-01-17 12:02:08 -0800
committerRichard Henderson <rth@twiddle.net>2017-01-17 12:02:08 -0800
commit39f099ec9d6d420b6fe6f7f4f8ed80ae29c65ff2 (patch)
treeec515d8cf3d0f04629dda46f269cad2bc0fa2069 /tcg
parent9bf38308f603680ca9b8d9a71e954d4c8a982d0c (diff)
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tcg/i386: Always use TZCNT when available
I think this is cleaner than sometimes using BSF. Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg')
-rw-r--r--tcg/i386/tcg-target.inc.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c
index 6489b73..5918008 100644
--- a/tcg/i386/tcg-target.inc.c
+++ b/tcg/i386/tcg-target.inc.c
@@ -1143,10 +1143,14 @@ static void tcg_out_movcond64(TCGContext *s, TCGCond cond, TCGReg dest,
static void tcg_out_ctz(TCGContext *s, int rexw, TCGReg dest, TCGReg arg1,
TCGArg arg2, bool const_a2)
{
- if (const_a2) {
- tcg_debug_assert(have_bmi1);
- tcg_debug_assert(arg2 == (rexw ? 64 : 32));
+ if (have_bmi1) {
tcg_out_modrm(s, OPC_TZCNT + rexw, dest, arg1);
+ if (const_a2) {
+ tcg_debug_assert(arg2 == (rexw ? 64 : 32));
+ } else {
+ tcg_debug_assert(dest != arg2);
+ tcg_out_cmov(s, TCG_COND_LTU, rexw, dest, arg2);
+ }
} else {
tcg_debug_assert(dest != arg2);
tcg_out_modrm(s, OPC_BSF + rexw, dest, arg1);