rtl-optimization/103075 - avoid ICEing on unfolded int-to-float converts
Commit Message
The following avoids asserting in exact_int_to_float_conversion_p that
the argument is not constant which it in fact can be with
-frounding-math and inexact int-to-float conversions. Say so.
Bootstrap & regtest running on x86_64-unknown-linux-gnu.
2021-11-04 Richard Biener <rguenther@suse.de>
PR rtl-optimization/103075
* simplify-rtx.c (exact_int_to_float_conversion_p): Return
false for a VOIDmode operand.
* gcc.dg/pr103075.c: New testcase.
---
gcc/simplify-rtx.c | 8 +++++---
gcc/testsuite/gcc.dg/pr103075.c | 8 ++++++++
2 files changed, 13 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr103075.c
@@ -899,10 +899,12 @@ simplify_context::simplify_unary_operation (rtx_code code, machine_mode mode,
static bool
exact_int_to_float_conversion_p (const_rtx op)
{
- int out_bits = significand_size (GET_MODE_INNER (GET_MODE (op)));
machine_mode op0_mode = GET_MODE (XEXP (op, 0));
- /* Constants shouldn't reach here. */
- gcc_assert (op0_mode != VOIDmode);
+ /* Constants can reach here with -frounding-math, if they do then
+ the conversion isn't exact. */
+ if (op0_mode == VOIDmode)
+ return false;
+ int out_bits = significand_size (GET_MODE_INNER (GET_MODE (op)));
int in_prec = GET_MODE_UNIT_PRECISION (op0_mode);
int in_bits = in_prec;
if (HWI_COMPUTABLE_MODE_P (op0_mode))
new file mode 100644
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-O -frounding-math" } */
+
+float
+foo (void)
+{
+ return (float) 0x1699925 * 1.1;
+}