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| author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2014-06-25 11:54:31 -0500 |
|---|---|---|
| committer | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2014-07-07 15:41:27 -0500 |
| commit | 87868c2418fb74357757e3b739ce5b76b17a8929 (patch) | |
| tree | 9ec2b1d9a4c0cf6af2a4306e09a11fc992bea94c /sysdeps/powerpc/powerpc64/power7 | |
| parent | 07aedd78b095093e866efd4809a80090e2b91a0b (diff) | |
| download | glibc-87868c2418fb74357757e3b739ce5b76b17a8929.tar.gz glibc-87868c2418fb74357757e3b739ce5b76b17a8929.tar.xz glibc-87868c2418fb74357757e3b739ce5b76b17a8929.zip | |
PowerPC: Align power7 memcpy using VSX to quadword
This patch changes power7 memcpy to use VSX instructions only when memory is aligned to quardword. It is to avoid unaligned kernel traps on non-cacheable memory (for instance, memory-mapped I/O).
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power7')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power7/memcpy.S | 22 |
1 files changed, 4 insertions, 18 deletions
diff --git a/sysdeps/powerpc/powerpc64/power7/memcpy.S b/sysdeps/powerpc/powerpc64/power7/memcpy.S index bbfd381b1b..58d9b1276d 100644 --- a/sysdeps/powerpc/powerpc64/power7/memcpy.S +++ b/sysdeps/powerpc/powerpc64/power7/memcpy.S @@ -36,16 +36,11 @@ EALIGN (memcpy, 5, 0) ble cr1, L(copy_LT_32) /* If move < 32 bytes use short move code. */ -#ifdef __LITTLE_ENDIAN__ -/* In little-endian mode, power7 takes an alignment trap on any lxvd2x - or stxvd2x crossing a 32-byte boundary, so ensure the aligned_copy - loop is only used for quadword aligned copies. */ +/* Align copies using VSX instructions to quadword. It is to avoid alignment + traps when memcpy is used on non-cacheable memory (for instance, memory + mapped I/O). */ andi. 10,3,15 clrldi 11,4,60 -#else - andi. 10,3,7 /* Check alignment of DST. */ - clrldi 11,4,61 /* Check alignment of SRC. */ -#endif cmpld cr6,10,11 /* SRC and DST alignments match? */ mr dst,3 @@ -53,13 +48,9 @@ EALIGN (memcpy, 5, 0) beq L(aligned_copy) mtocrf 0x01,0 -#ifdef __LITTLE_ENDIAN__ clrldi 0,0,60 -#else - clrldi 0,0,61 -#endif -/* Get the DST and SRC aligned to 8 bytes (16 for little-endian). */ +/* Get the DST and SRC aligned to 16 bytes. */ 1: bf 31,2f lbz 6,0(src) @@ -79,14 +70,12 @@ EALIGN (memcpy, 5, 0) stw 6,0(dst) addi dst,dst,4 8: -#ifdef __LITTLE_ENDIAN__ bf 28,16f ld 6,0(src) addi src,src,8 std 6,0(dst) addi dst,dst,8 16: -#endif subf cnt,0,cnt /* Main aligned copy loop. Copies 128 bytes at a time. */ @@ -298,9 +287,6 @@ L(copy_LE_8): .align 4 L(copy_GE_32_unaligned): clrldi 0,0,60 /* Number of bytes until the 1st dst quadword. */ -#ifndef __LITTLE_ENDIAN__ - andi. 10,3,15 /* Check alignment of DST (against quadwords). */ -#endif srdi 9,cnt,4 /* Number of full quadwords remaining. */ beq L(copy_GE_32_unaligned_cont) |