On 24/01/2019 15:36, Wilco Dijkstra wrote: > The TST instruction no longer matches in all cases due to changes in > Combine. The fix is simple, we now need to allow a subreg as well when > selecting the cc_mode. This fixes the tst_5.c and tst_6.c failures. > > AArch64 regress & bootstrap OK. > > ChangeLog: > 2019-01-23 Wilco Dijkstra <wdijk...@arm.com> > > PR rtl-optimization/87763 > * config/aarch64/aarch64.c (aarch64_select_cc_mode): > Allow SUBREG when matching CC_NZmode compare. > > -- > > diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c > index > a0006dc1f8a921dd83209d4404132a1fe3cfcd1e..237428d28b4f20ddfefee83ed020e209011147a0 > 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -7120,7 +7120,7 @@ aarch64_select_cc_mode (RTX_CODE code, rtx x, rtx y) > > /* Equality comparisons of short modes against zero can be performed > using the TST instruction with the appropriate bitmask. */ > - if (y == const0_rtx && REG_P (x) > + if (y == const0_rtx && (REG_P (x) || SUBREG_P (x)) > && (code == EQ || code == NE) > && (GET_MODE (x) == HImode || GET_MODE (x) == QImode)) > return CC_NZmode; >
OK. R.
