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authorFrancisco Jerez <[email protected]>2018-01-26 11:48:02 -0800
committerFrancisco Jerez <[email protected]>2018-02-27 11:42:39 -0800
commitcb309d27c52e9a6eeeedbddb82a0f6eb75a6f263 (patch)
tree26876a8343d5d645773fd5dda9d9ace97724abaa /src/intel/compiler
parent69b4a9d21d00e1f72b52e818cc059ee1642f263e (diff)
intel/ir: Fix invalid type aliasing with undefined behavior in test_eu_compact.
test_fuzz_compact_instruction() was attempting to modify the uint64_t data array of a brw_inst through a pointer to uint32_t, which has undefined behavior. This was causing the test_eu_compact unit test to fail mysteriously for me on GCC 7 with some additional harmless-looking changes I had applied to my tree, which happened to affect the order instructions are emitted by GCC causing the bit twiddling to be done after the clear_pad_bits() call which is supposed to overwrite the same data through a pointer of different type, leading to data corruption. A similar failure has been reported by Vinson Lee on the master branch built with GCC 8. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105052 Tested-by: Vinson Lee <[email protected]> Reviewed-by: Matt Turner <[email protected]>
Diffstat (limited to 'src/intel/compiler')
-rw-r--r--src/intel/compiler/test_eu_compact.cpp6
1 files changed, 3 insertions, 3 deletions
diff --git a/src/intel/compiler/test_eu_compact.cpp b/src/intel/compiler/test_eu_compact.cpp
index 1532e3b9840..f6924abd368 100644
--- a/src/intel/compiler/test_eu_compact.cpp
+++ b/src/intel/compiler/test_eu_compact.cpp
@@ -149,13 +149,13 @@ test_fuzz_compact_instruction(struct brw_codegen *p, brw_inst src)
for (int bit1 = 0; bit1 < 128; bit1++) {
brw_inst instr = src;
- uint32_t *bits = (uint32_t *)&instr;
+ uint64_t *bits = instr.data;
if (skip_bit(p->devinfo, &src, bit1))
continue;
- bits[bit0 / 32] ^= (1 << (bit0 & 31));
- bits[bit1 / 32] ^= (1 << (bit1 & 31));
+ bits[bit0 / 64] ^= (1ull << (bit0 & 63));
+ bits[bit1 / 64] ^= (1ull << (bit1 & 63));
clear_pad_bits(p->devinfo, &instr);