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| author | Andrew Pinski <quic_apinski@quicinc.com> | 2024-01-25 13:45:59 -0800 |
|---|---|---|
| committer | Andrew Pinski <quic_apinski@quicinc.com> | 2024-01-25 21:02:19 -0800 |
| commit | 0c2583dc2575f3f64e3d09e12c296eb56f01916d (patch) | |
| tree | 224e6e941fc89f6035a2253fc20ef92da4ef34d8 /gcc | |
| parent | f22a7ae8a96f7e5e330b12bd5045424619aa4926 (diff) | |
| download | gcc-0c2583dc2575f3f64e3d09e12c296eb56f01916d.zip gcc-0c2583dc2575f3f64e3d09e12c296eb56f01916d.tar.gz gcc-0c2583dc2575f3f64e3d09e12c296eb56f01916d.tar.bz2 | |
aarch64: Fix/avoid undefinedness in aarch64_classify_index [PR100212]
The problem here is we don't check the return value of exact_log2
and always use that result as shifter. This fixes the issue by avoiding
the shift if the value was `-1` (which means the value was not exact a power of 2);
in this case we could either check if the values was equal to -1 or not equal to because
we then assign -1 to shift if the constant value was not equal. I chose `!=` as
it seemed to be more obvious of what the code is doing.
Committed as obvious after a build/test for aarch64-linux-gnu.
gcc/ChangeLog:
PR target/100212
* config/aarch64/aarch64.cc (aarch64_classify_index): Avoid
undefined shift after the call to exact_log2.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/aarch64/aarch64.cc | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc index d2014ce..19c608b 100644 --- a/gcc/config/aarch64/aarch64.cc +++ b/gcc/config/aarch64/aarch64.cc @@ -10246,7 +10246,9 @@ aarch64_classify_index (struct aarch64_address_info *info, rtx x, type = ADDRESS_REG_UXTW; index = XEXP (XEXP (x, 0), 0); shift = exact_log2 (INTVAL (XEXP (XEXP (x, 0), 1))); - if (INTVAL (XEXP (x, 1)) != (HOST_WIDE_INT)0xffffffff << shift) + /* Avoid undefined code dealing with shift being -1. */ + if (shift != -1 + && INTVAL (XEXP (x, 1)) != (HOST_WIDE_INT)0xffffffff << shift) shift = -1; } /* (and:DI (ashift:DI (reg:DI) (const_int shift)) |