https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123501
Bug ID: 123501
Summary: [16 Regression] [RISCV] [Miscompile] GCC - riscv64
target, miscompiles at -O3 since
0b129b8b368635b3170aa276809d644dc99e3256
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: skothadiya at whileone dot in
Target Milestone: ---
Created attachment 63296
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63296&action=edit
Attached reduced testcase
Description:
The testcase code involves for loops on various datatypes, compiles correctly
on x86_64 and produces the expected output. However, when compiled for the
riscv64 architecture, the resulting binary yields an incorrect value. The
expected output is 1, but the program returns 0. This miscompilation occurs
specifically with optimization enabled at level -O3.
COMMANDS:
/sujayk/CIFUZZR/riscv-gnu-toolchain-build/bin/riscv64-unknown-linux-gnu-gcc
-march=rv64gcv_zvl256b -mrvv-vector-bits=zvl -mrvv-max-lmul=m8 -O3 red.c -o
user-config.out -fsigned-char -fno-strict-aliasing -fwrapv
-Wno-unknown-warning-option -Werror -Wfatal-errors -Wall -Wformat
-Wno-int-in-bool-context -Wno-dangling-pointer
-Wno-compare-distinct-pointer-types -Wno-overflow -Wuninitialized
-Warray-bounds -Wreturn-type -Wno-unused-function -Wno-unused-variable
-Wno-unused-but-set-variable -Wno-unused-value -Wno-address -Wno-bool-compare
-Wno-pointer-sign -Wno-bool-operation -Wno-tautological-compare
-Wno-self-assign -Wno-implicit-const-int-float-conversion
-Wno-constant-conversion -Wno-unused-value
-Wno-tautological-constant-out-of-range-compare -Wno-constant-logical-operand
-Wno-parentheses-equality -Wno-pointer-sign
QEMU_CPU=rv64,vlen=256,rvv_ta_all_1s=true,rvv_ma_all_1s=true,v=true,vext_spec=v1.0,zve32f=true,zve64f=true
timeout --verbose -k 0.1 4 /riscv-gnu-toolchain-build/bin/qemu-riscv64
user-config.out 1
0
//Expected Output: 1
//Actual Output: 0
-- testcase (red.c) --
int printf(const char *, ...);
long long b;
_Bool a=1;
char e[13];
int main() {
for (long h=0; h<13; ++h)
e[h] = 110;
for (int i=5; i<9; i++)
for (int k=0; k<1031; k++) {
int l = e[0] ? e[i] : 0;
a = l ? a:l;
}
b = (int)a;
printf("%llu\n", b);
}
The issue is Found via fuzzer.
