xorps-sse2.c: Adjust tune-ctrl to fix testsuite failures
Disables a specific SSE optimization in xorps-sse2.c test case to resolve assembler scan failures.
Test failures in gcc.target/i386/xorps-sse2.c were observed due to unexpected assembler output for pxor and xorps instructions when a particular SSE optimization was enabled. This commit modifies the test case to explicitly disable the sse_packed_single_insn_optimal tune-control knob, resolving the assembler scan failures.
In Details
The TARGET_SSE_PACKED_SINGLE_INSN_OPTIMAL machine-dependent option influences instruction selection for SSE operations on packed single-precision floating-point values. When enabled, it may lead to the generation of pxor instructions, causing testsuite failures with scan-assembler-not pxor. This change disables this specific knob using -mtune-ctrl for the affected test case.
- SSE
- Streaming SIMD Extensions, a set of CPU instructions for parallel processing of data, primarily floating-point numbers.
- xorps
- An SSE instruction that performs a bitwise XOR operation on packed single-precision floating-point values.
- pxor
- An SSE instruction that performs a bitwise XOR operation on packed integer or floating-point values.
- scan-assembler
- A testsuite utility that checks if the generated assembly code contains specific patterns or avoids others.
- tune-ctrl
- A GCC option that allows fine-grained control over specific performance-related tuning behaviors, often disabling or enabling them for testing purposes.