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| author | Tom de Vries <tdevries@suse.de> | 2020-09-10 15:54:14 +0200 |
|---|---|---|
| committer | Tom de Vries <tdevries@suse.de> | 2020-09-10 21:30:33 +0200 |
| commit | af47a2035a4882e6d4506e3d00b5a42414e3ee2b (patch) | |
| tree | 84adb9201f74b952e64fe1c209f0bace9098420d | |
| parent | a8f9b4c54cc350625accbb2c6b4005acb42d4c2e (diff) | |
| download | gcc-af47a2035a4882e6d4506e3d00b5a42414e3ee2b.zip gcc-af47a2035a4882e6d4506e3d00b5a42414e3ee2b.tar.gz gcc-af47a2035a4882e6d4506e3d00b5a42414e3ee2b.tar.bz2 | |
[nvptx] Fix printing of 128-bit constant
Currently, for this code from c-c++-common/spec-barrier-1.c:
...
__int128 g = 9;
...
we generate:
...
// BEGIN GLOBAL VAR DEF: g
.visible .global .align 8 .u64 g[2] = { 9, 9 };
...
and consequently the test-case fails in execution.
The problem is caused by a shift in nvptx_assemble_value:
...
val >>= part * BITS_PER_UNIT;
...
where the shift amount is equal to the number of bits in val, which is
undefined behaviour.
Fix this by detecting the situation and setting val to 0.
Tested on nvptx.
gcc/ChangeLog:
PR target/97004
* config/nvptx/nvptx.c (nvptx_assemble_value): Handle shift by
number of bits in shift operand.
| -rw-r--r-- | gcc/config/nvptx/nvptx.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c index 0376ad6..ffcbe59 100644 --- a/gcc/config/nvptx/nvptx.c +++ b/gcc/config/nvptx/nvptx.c @@ -2054,7 +2054,11 @@ nvptx_assemble_value (unsigned HOST_WIDE_INT val, unsigned size) for (unsigned part = 0; size; size -= part) { - val >>= part * BITS_PER_UNIT; + if (part * BITS_PER_UNIT == HOST_BITS_PER_WIDE_INT) + /* Avoid undefined behaviour. */ + val = 0; + else + val >>= (part * BITS_PER_UNIT); part = init_frag.size - init_frag.offset; part = MIN (part, size); |