OpenE2K
/
qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

target/ppc: avoid int32 multiply overflow in int_helper.c 

Coverity is not thrilled about the multiply operations being done in
ger_rank8() and ger_rank2(), giving an error like the following:

Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
    Potentially overflowing expression "sextract32(a, 4 * i, 4) *
sextract32(b, 4 * i, 4)" with type "int" (32 bits, signed) is evaluated
using 32-bit arithmetic, and then used in a context that expects an
expression of type "int64_t" (64 bits, signed).

Fix both instances where this occur by adding an int64_t cast in the
first operand, forcing the result to be 64 bit.

Fixes: Coverity CID 1489444, 1489443
Fixes: 345531533f ("target/ppc: Implemented xvi*ger* instructions")
Cc: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Cc: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20220602141449.118173-1-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This commit is contained in:
Daniel Henrique Barboza 2022-06-02 11:14:49 -03:00
parent 78d6b5d33a
commit feeef6b6dd
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
target/ppc/int_helper.c
View File

@ -789,7 +789,7 @@ static int64_t ger_rank8(uint32_t a, uint32_t b, uint32_t mask)
int64_t psum = 0;
for (int i = 0; i < 8; i++, mask >>= 1) {
if (mask & 1) {
psum += sextract32(a, 4 * i, 4) * sextract32(b, 4 * i, 4);
psum += (int64_t)sextract32(a, 4 * i, 4) * sextract32(b, 4 * i, 4);
}
}
return psum;
@ -811,7 +811,8 @@ static int64_t ger_rank2(uint32_t a, uint32_t b, uint32_t mask)
int64_t psum = 0;
for (int i = 0; i < 2; i++, mask >>= 1) {
if (mask & 1) {
psum += sextract32(a, 16 * i, 16) * sextract32(b, 16 * i, 16);
psum += (int64_t)sextract32(a, 16 * i, 16) *
sextract32(b, 16 * i, 16);
}
}
return psum;