On 7/31/24 9:55 AM, Robin Dapp wrote:
Hi,
in PR116149 we choose a wrong vector length which causes wrong values in
a reduction. The problem happens in avlprop where we choose the
number of units in the instruction's mode as vector length. For the
non-scalar variants the respective operand has the correct non-widened
mode. For the scalar variants, however, the same operand has a scalar
mode which obviously only has one unit. This makes us choose VL = 1
leaving three elements undisturbed (so potentially -1). Those end up
in the reduction causing the wrong result.
This patch adjusts the mode_idx just for the scalar variants of the
affected instruction patterns.
Regards
Robin
gcc/ChangeLog:
PR target/116149
* config/riscv/vector.md: Fix mode_idx attribute of scalar
widen add/sub variants.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/pr116149.c: New test.
OK
jeff
