gbdev/rgbds
1
0
Fork 0
mirror of https://github.com/gbdev/rgbds.git synced 2025-11-21 10:42:07 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix calculation of 2**30

Browse Source 
In exponent(), 'base *= base;' should not run
when base is 65536, since it overflows an int32_t.

This also optimizes exponent() based on
gcc and clang -O3 test cases in godbolt.org.
This commit is contained in:
Rangi
2021-02-17 09:25:02 -05:00
parent d049ffc0f0
commit 748e7dd4c7
3 changed files with 11 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
src/asm/rpn.c
View File

@@ -283,14 +283,16 @@ static int32_t shift(int32_t shiftee, int32_t amount)
}
}
static int32_t exponent(int32_t base, int32_t power)
static int32_t exponent(int32_t base, uint32_t power)
{
int32_t result = 1;
while (power) {
for (;;) {
if (power % 2)
result *= base;
power /= 2;
if (!power)
break;
base *= base;
}