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| author | Jeff Law <jlaw@ventanamicro.com> | 2025-05-15 09:03:13 -0600 |
|---|---|---|
| committer | Jeff Law <jlaw@ventanamicro.com> | 2025-05-15 09:14:10 -0600 |
| commit | 87d0daab1ec9d5c901295e8045cbd67f80b2fa23 (patch) | |
| tree | b94ad18b7f6d90a2e53993b5dc8968daf8e06b03 | |
| parent | 0c430503f2849ebb20105695b8ad40d43d797c7b (diff) | |
| download | gcc-87d0daab1ec9d5c901295e8045cbd67f80b2fa23.zip gcc-87d0daab1ec9d5c901295e8045cbd67f80b2fa23.tar.gz gcc-87d0daab1ec9d5c901295e8045cbd67f80b2fa23.tar.bz2 | |
[RISC-V][PR target/120223] Don't use bset/binv for XTHEADBS
Thead has the XTHEADBB extension which has a lot of overlap with Zbb. I made
the incorrect assumption that XTHEADBS would largely be like Zbs when
generalizing Shreya's work.
As a result we can't use the operation synthesis code for IOR/XOR because we
don't have binv/bset like capabilities. I should have double checked on
XTHEADBS, my bad.
Anyway, the fix is trivial. Don't allow bset/binv based on XTHEADBS.
Already spun in my tester. Spinning in the pre-commit CI system now.
PR target/120223
gcc/
* config/riscv/riscv.cc (synthesize_ior_xor): XTHEADBS does not have
single bit manipulations.
gcc/testsuite/
* gcc.target/riscv/pr120223.c: New test.
| -rw-r--r-- | gcc/config/riscv/riscv.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/riscv/pr120223.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc index d28aee4..d996965 100644 --- a/gcc/config/riscv/riscv.cc +++ b/gcc/config/riscv/riscv.cc @@ -14227,7 +14227,7 @@ synthesize_ior_xor (rtx_code code, rtx operands[3]) { /* Trivial cases that don't need synthesis. */ if (SMALL_OPERAND (INTVAL (operands[2])) - || ((TARGET_ZBS || TARGET_XTHEADBS || TARGET_ZBKB) + || ((TARGET_ZBS || TARGET_ZBKB) && single_bit_mask_operand (operands[2], word_mode))) return false; @@ -14264,7 +14264,7 @@ synthesize_ior_xor (rtx_code code, rtx operands[3]) /* If we're flipping all but a small number of bits we can pre-flip the outliers, then flip all the bits, which would restore those bits that were pre-flipped. */ - if ((TARGET_ZBS || TARGET_XTHEADBS || TARGET_ZBKB) + if ((TARGET_ZBS || TARGET_ZBKB) && budget < 0 && code == XOR && popcount_hwi (~INTVAL (operands[2])) < original_budget) diff --git a/gcc/testsuite/gcc.target/riscv/pr120223.c b/gcc/testsuite/gcc.target/riscv/pr120223.c new file mode 100644 index 0000000..fae21b6 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/pr120223.c @@ -0,0 +1,4 @@ +/* { dg-do compile } */ +/* { dg-options "-mcpu=thead-c906" } */ +long foo(long x) { return x ^ 0x80000000; } + |