tcg/aarch64: Generate CBNZ for TSTNE of UINT32_MAX

... and the inverse, CBZ for TSTEQ.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-10-28 03:37:23 +00:00
parent 92a11b935d
commit 34aff3c2e0

View file

@ -1463,6 +1463,12 @@ static void tcg_out_brcond(TCGContext *s, TCGType ext, TCGCond c, TCGArg a,
break;
case TCG_COND_TSTEQ:
case TCG_COND_TSTNE:
/* tst xN,0xffffffff; b.ne L -> cbnz wN,L */
if (b_const && b == UINT32_MAX) {
ext = TCG_TYPE_I32;
need_cmp = false;
break;
}
/* tst xN,1<<B; b.ne L -> tbnz xN,B,L */
if (b_const && is_power_of_2(b)) {
tbit = ctz64(b);