diff options
| author | Richard Earnshaw <rearnsha@arm.com> | 2020-11-24 16:21:17 +0000 |
|---|---|---|
| committer | Richard Earnshaw <rearnsha@arm.com> | 2020-11-24 16:35:11 +0000 |
| commit | f30a9a8d9e06ae2bf38e0d25e3ca6095212c78e9 (patch) | |
| tree | 769e77479c0bf8e207a94679f520cbb09d520670 | |
| parent | 13f93cf5336ec0085277b9a5ef88c02359527170 (diff) | |
| download | gcc-f30a9a8d9e06ae2bf38e0d25e3ca6095212c78e9.zip gcc-f30a9a8d9e06ae2bf38e0d25e3ca6095212c78e9.tar.gz gcc-f30a9a8d9e06ae2bf38e0d25e3ca6095212c78e9.tar.bz2 | |
arm: correctly handle negating INT_MIN in arm_split_atomic_op [PR97534]
arm_split_atomic_op handles subtracting a constant by converting it
into addition of the negated constant. But if the type of the operand
is int and the constant is -1 we currently end up generating invalid
RTL which can lead to an abort later on.
The problem is that in a HOST_WIDE_INT, INT_MIN is represented as
0xffffffff80000000 and the negation of this is 0x0000000080000000, but
that's not a valid constant for use in SImode operations.
The fix is straight-forward which is to use gen_int_mode rather than
simply GEN_INT. This knows how to correctly sign-extend the negated
constant when this is needed.
gcc/
PR target/97534
* config/arm/arm.c (arm_split_atomic_op): Use gen_int_mode when
negating a const_int.
gcc/testsuite
* gcc.dg/pr97534.c: New test.
| -rw-r--r-- | gcc/config/arm/arm.c | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr97534.c | 9 |
2 files changed, 10 insertions, 1 deletions
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 568e153..56ed556 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -30824,7 +30824,7 @@ arm_split_atomic_op (enum rtx_code code, rtx old_out, rtx new_out, rtx mem, case MINUS: if (CONST_INT_P (value)) { - value = GEN_INT (-INTVAL (value)); + value = gen_int_mode (-INTVAL (value), wmode); code = PLUS; } /* FALLTHRU */ diff --git a/gcc/testsuite/gcc.dg/pr97534.c b/gcc/testsuite/gcc.dg/pr97534.c new file mode 100644 index 0000000..b363a32 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr97534.c @@ -0,0 +1,9 @@ +/* PR target/97534 - ICE in decompose on arm*-*-*. */ +/* { dg-do compile } */ +/* { dg-options "-std=c11 -O2 -g" } */ + +int f (int a) +{ + int b; + __atomic_fetch_sub(&b, (int)(-__INT_MAX__ - 1), (int)0); +} |