From: Richard Earnshaw <[email protected]>
There was UB in arm_canonicalize_comparison if it is called with
both operands of type VOIDmode. Avoid this by first handling
floating-point types, then returning if we are left with anything
other than an integer mode. For belt-and-braces also check that
the mode does not require a mask larger than HOST_WIDE_INT.
gcc/ChangeLog:
PR target/122999
* config/arm/arm.cc (arm_canonicalize_comparison): Defer
initializing maxval until we know we are dealing with an
integer mode.
---
gcc/config/arm/arm.cc | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
index 20d3f1f4578b..1f413b61d5f6 100644
--- a/gcc/config/arm/arm.cc
+++ b/gcc/config/arm/arm.cc
@@ -5700,8 +5700,6 @@ arm_canonicalize_comparison (int *code, rtx *op0, rtx *op1,
if (mode == VOIDmode)
mode = GET_MODE (*op1);
- maxval = (HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (mode) - 1)) - 1;
-
/* For floating-point comparisons, prefer >= and > over <= and < since
the former are supported by VSEL on some architectures. Only do this
if both operands are registers. */
@@ -5718,6 +5716,13 @@ arm_canonicalize_comparison (int *code, rtx *op0, rtx *op1,
return;
}
+ /* Everything below assumes an integer mode. */
+ if (GET_MODE_CLASS (mode) != MODE_INT
+ || GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT)
+ return;
+
+ maxval = (HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (mode) - 1)) - 1;
+
/* For DImode, we have GE/LT/GEU/LTU comparisons (with cmp/sbc). In
ARM mode we can also use cmp/cmpeq for GTU/LEU. GT/LE must be
either reversed or (for constant OP1) adjusted to GE/LT.
