[Bug target/114396] [14] RISC-V rv64gcv vector: Runtime mismatch at -O3 with -fwrapv

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396

--- Comment #4 from Jonathan Wakely  ---
$ ~/gcc/14/bin/aarch64-unknown-linux-gnu-gcc -O3 -fwrapv  -fno-vect-cost-model
-fwrapv red.c -o red.out
$ ./red.out
decimal: 32693
hex: 7FB5
$ ~/gcc/14/bin/aarch64-unknown-linux-gnu-gcc  red.c -o red.out
$ ./red.out
decimal: 2283
hex: 8EB

[Bug target/114396] [14] RISC-V rv64gcv vector: Runtime mismatch at -O3 with -fwrapv

[rdapp at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396

--- Comment #3 from Robin Dapp  ---
-O3 -mavx2 -fno-vect-cost-model -fwrapv seems to be sufficient.

[Bug target/114396] [14] RISC-V rv64gcv vector: Runtime mismatch at -O3 with -fwrapv

[rdapp at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396

Robin Dapp  changed:

   What|Removed |Added

 Target|riscv*-*-*  |x86_64-*-* riscv*-*-*

--- Comment #2 from Robin Dapp  ---
At first glance it doesn't really look like a target issue.

Tried it on x86 and it fails as well with
-O3 -march=native pr114396.c -fno-vect-cost-model -fwrapv

short a = 0xF;
short b[16];

int main() {
for (int e = 0; e < 9; e += 1)
b[e] = a *= 0x5;

if (a != 2283)
__builtin_abort ();
}

[Bug target/114396] [14] RISC-V rv64gcv vector: Runtime mismatch at -O3 with -fwrapv

[patrick at rivosinc dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114396

--- Comment #1 from Patrick O'Neill  ---
Here's the result when running with -fwrapv on rv64gcv at O2:

> /scratch/tc-testing/tc-mar-18/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc 
> -march=rv64gcv -O2 red.c -o red.out -fwrapv
> /scratch/tc-testing/tc-mar-18/build-rv64gcv/bin/qemu-riscv64 red.out
decimal: 2283
hex: 8EB