Hi!
As reported in PR93312, the:
> > > > > > * config/arm/arm.c (clear_operation_p): New function.
change broke RTL checking bootstrap.
On the testcase from the PR (which is distilled from libgcc2.c, so I think
we don't need to add it into testsuite) we ICE because SET_DEST (elt) is
not a REG, but SUBREG. The code uses REGNO on it, which is invalid, but
only stores it into a variable, then performs REG_P (reg) check,
determines it is not a REG and bails early.
The following patch just moves the regno variable initialization after that
check, it isn't used in between. And, as a small optimization, because
reg doesn't change, doesn't use REGNO (reg) a second time to set last_regno.
Ok for trunk if it passes bootstrap/regtest?
2020-01-17 Jakub Jelinek <ja...@redhat.com>
PR target/93312
* config/arm/arm.c (clear_operation_p): Don't use REGNO until
after checking the argument is a REG. Don't use REGNO (reg)
again to set last_regno, reuse regno variable instead.
--- gcc/config/arm/arm.c.jj 2020-01-17 09:31:28.594195284 +0100
+++ gcc/config/arm/arm.c 2020-01-17 19:30:47.747756756 +0100
@@ -13779,7 +13779,6 @@ clear_operation_p (rtx op, bool vfp)
return false;
reg = SET_DEST (elt);
- regno = REGNO (reg);
zero = SET_SRC (elt);
if (!REG_P (reg)
@@ -13787,6 +13786,8 @@ clear_operation_p (rtx op, bool vfp)
|| zero != CONST0_RTX (SImode))
return false;
+ regno = REGNO (reg);
+
if (vfp)
{
if (i != 1 && regno != last_regno + 1)
@@ -13800,7 +13801,7 @@ clear_operation_p (rtx op, bool vfp)
return false;
}
- last_regno = REGNO (reg);
+ last_regno = regno;
}
return true;
Jakub
