diff options
| -rw-r--r-- | src/gallium/drivers/llvmpipe/lp_setup_tri.c | 46 |
1 files changed, 22 insertions, 24 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c index f0c74f8040a..3b7fd5d154a 100644 --- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c +++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c @@ -440,30 +440,28 @@ do_triangle_ccw(struct lp_setup_context *setup, } /* - * __fls: find last set bit in word - * @word: The word to search + * Round to nearest less or equal power of two of the input. * - * Undefined if no zero exists, so code should check against ~0UL first. + * Undefined if no bit set exists, so code should check against 0 first. */ -#if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86) -static inline unsigned fls(unsigned word) +static INLINE uint32_t +floor_pot(uint32_t n) { - asm("bsr %1,%0" - : "=r" (word) - : "rm" (word)); - return word; -} + assert(n); +#if defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86) + asm("bsr %1,%0" + : "=r" (n) + : "rm" (n)); + return 1 << n; #else -static inline unsigned fls(unsigned n) -{ - n |= (n >> 1); - n |= (n >> 2); - n |= (n >> 4); - n |= (n >> 8); - n |= (n >> 16); - return n - (n >> 1); -} + n |= (n >> 1); + n |= (n >> 2); + n |= (n >> 4); + n |= (n >> 8); + n |= (n >> 16); + return n - (n >> 1); #endif +} boolean @@ -477,14 +475,14 @@ lp_setup_bin_triangle( struct lp_setup_context *setup, /* What is the largest power-of-two boundary this triangle crosses: */ - int dx = 1 << fls((bbox->x0 ^ bbox->x1) | - (bbox->y0 ^ bbox->y1)); + int dx = floor_pot((bbox->x0 ^ bbox->x1) | + (bbox->y0 ^ bbox->y1)); /* The largest dimension of the rasterized area of the triangle - * (aligned to a 4x4 grid), rounded up to the next power of two: + * (aligned to a 4x4 grid), rounded down to the nearest power of two: */ - int sz = 1 << fls((bbox->x1 - (bbox->x0 & ~3)) | - (bbox->y1 - (bbox->y0 & ~3))); + int sz = floor_pot((bbox->x1 - (bbox->x0 & ~3)) | + (bbox->y1 - (bbox->y0 & ~3))); if (nr_planes == 3) { if (sz < 4 && dx < 64) |