diff options
Diffstat (limited to 'arch/tile/lib/memset_32.c')
| -rw-r--r-- | arch/tile/lib/memset_32.c | 105 |
1 files changed, 0 insertions, 105 deletions
diff --git a/arch/tile/lib/memset_32.c b/arch/tile/lib/memset_32.c index 9a7837d11f7d..2042bfe6595f 100644 --- a/arch/tile/lib/memset_32.c +++ b/arch/tile/lib/memset_32.c @@ -23,11 +23,7 @@ void *memset(void *s, int c, size_t n) int n32; uint32_t v16, v32; uint8_t *out8 = s; -#if !CHIP_HAS_WH64() - int ahead32; -#else int to_align32; -#endif /* Experimentation shows that a trivial tight loop is a win up until * around a size of 20, where writing a word at a time starts to win. @@ -58,21 +54,6 @@ void *memset(void *s, int c, size_t n) return s; } -#if !CHIP_HAS_WH64() - /* Use a spare issue slot to start prefetching the first cache - * line early. This instruction is free as the store can be buried - * in otherwise idle issue slots doing ALU ops. - */ - __insn_prefetch(out8); - - /* We prefetch the end so that a short memset that spans two cache - * lines gets some prefetching benefit. Again we believe this is free - * to issue. - */ - __insn_prefetch(&out8[n - 1]); -#endif /* !CHIP_HAS_WH64() */ - - /* Align 'out8'. We know n >= 3 so this won't write past the end. */ while (((uintptr_t) out8 & 3) != 0) { *out8++ = c; @@ -93,90 +74,6 @@ void *memset(void *s, int c, size_t n) /* This must be at least 8 or the following loop doesn't work. */ #define CACHE_LINE_SIZE_IN_WORDS (CHIP_L2_LINE_SIZE() / 4) -#if !CHIP_HAS_WH64() - - ahead32 = CACHE_LINE_SIZE_IN_WORDS; - - /* We already prefetched the first and last cache lines, so - * we only need to do more prefetching if we are storing - * to more than two cache lines. - */ - if (n32 > CACHE_LINE_SIZE_IN_WORDS * 2) { - int i; - - /* Prefetch the next several cache lines. - * This is the setup code for the software-pipelined - * loop below. - */ -#define MAX_PREFETCH 5 - ahead32 = n32 & -CACHE_LINE_SIZE_IN_WORDS; - if (ahead32 > MAX_PREFETCH * CACHE_LINE_SIZE_IN_WORDS) - ahead32 = MAX_PREFETCH * CACHE_LINE_SIZE_IN_WORDS; - - for (i = CACHE_LINE_SIZE_IN_WORDS; - i < ahead32; i += CACHE_LINE_SIZE_IN_WORDS) - __insn_prefetch(&out32[i]); - } - - if (n32 > ahead32) { - while (1) { - int j; - - /* Prefetch by reading one word several cache lines - * ahead. Since loads are non-blocking this will - * cause the full cache line to be read while we are - * finishing earlier cache lines. Using a store - * here causes microarchitectural performance - * problems where a victimizing store miss goes to - * the head of the retry FIFO and locks the pipe for - * a few cycles. So a few subsequent stores in this - * loop go into the retry FIFO, and then later - * stores see other stores to the same cache line - * are already in the retry FIFO and themselves go - * into the retry FIFO, filling it up and grinding - * to a halt waiting for the original miss to be - * satisfied. - */ - __insn_prefetch(&out32[ahead32]); - -#if CACHE_LINE_SIZE_IN_WORDS % 4 != 0 -#error "Unhandled CACHE_LINE_SIZE_IN_WORDS" -#endif - - n32 -= CACHE_LINE_SIZE_IN_WORDS; - - /* Save icache space by only partially unrolling - * this loop. - */ - for (j = CACHE_LINE_SIZE_IN_WORDS / 4; j > 0; j--) { - *out32++ = v32; - *out32++ = v32; - *out32++ = v32; - *out32++ = v32; - } - - /* To save compiled code size, reuse this loop even - * when we run out of prefetching to do by dropping - * ahead32 down. - */ - if (n32 <= ahead32) { - /* Not even a full cache line left, - * so stop now. - */ - if (n32 < CACHE_LINE_SIZE_IN_WORDS) - break; - - /* Choose a small enough value that we don't - * prefetch past the end. There's no sense - * in touching cache lines we don't have to. - */ - ahead32 = CACHE_LINE_SIZE_IN_WORDS - 1; - } - } - } - -#else /* CHIP_HAS_WH64() */ - /* Determine how many words we need to emit before the 'out32' * pointer becomes aligned modulo the cache line size. */ @@ -233,8 +130,6 @@ void *memset(void *s, int c, size_t n) n32 &= CACHE_LINE_SIZE_IN_WORDS - 1; } -#endif /* CHIP_HAS_WH64() */ - /* Now handle any leftover values. */ if (n32 != 0) { do { |