From f59a2d22a05272034e856b7a2dd7a3ab7864a2ae Mon Sep 17 00:00:00 2001 From: David Daney Date: Thu, 16 Aug 2012 11:15:22 -0700 Subject: MIPS: Optimize pgd_init and pmd_init On a dual issue processor GCC generates code that saves a couple of clock cycles per loop if we rearrange things slightly. Checking for p != end saves a SLTU per loop, moving the increment to the middle can let it dual issue on multi-issue processors. Signed-off-by: David Daney Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4249/ Signed-off-by: Ralf Baechle --- arch/mips/mm/pgtable-64.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'arch/mips') diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c index cda4e300eb0a..25407794edb4 100644 --- a/arch/mips/mm/pgtable-64.c +++ b/arch/mips/mm/pgtable-64.c @@ -26,17 +26,17 @@ void pgd_init(unsigned long page) p = (unsigned long *) page; end = p + PTRS_PER_PGD; - while (p < end) { + do { p[0] = entry; p[1] = entry; p[2] = entry; p[3] = entry; p[4] = entry; - p[5] = entry; - p[6] = entry; - p[7] = entry; p += 8; - } + p[-3] = entry; + p[-2] = entry; + p[-1] = entry; + } while (p != end); } #ifndef __PAGETABLE_PMD_FOLDED @@ -47,17 +47,17 @@ void pmd_init(unsigned long addr, unsigned long pagetable) p = (unsigned long *) addr; end = p + PTRS_PER_PMD; - while (p < end) { + do { p[0] = pagetable; p[1] = pagetable; p[2] = pagetable; p[3] = pagetable; p[4] = pagetable; - p[5] = pagetable; - p[6] = pagetable; - p[7] = pagetable; p += 8; - } + p[-3] = pagetable; + p[-2] = pagetable; + p[-1] = pagetable; + } while (p != end); } #endif -- cgit v1.2.3