#include <mach/ppc/asm.h>
#undef ASSEMBLER
+#define __APPLE_API_PRIVATE
+#include <machine/cpu_capabilities.h>
+#undef __APPLE_API_PRIVATE
+
+/* We use mode-independent "g" opcodes such as "srgi". These expand
+ * into word operations when targeting __ppc__, and into doubleword
+ * operations when targeting __ppc64__.
+ */
+#include <architecture/ppc/mode_independent_asm.h>
+
+
// *****************
// * S T R L C P Y *
// *****************
// The test maps any non-zero byte to zero, and any zero byte to 0x80,
// with one exception: 0x01 bytes preceeding the first zero are also
// mapped to 0x80.
+//
+// This algorithm is doubleword parallel in 64-bit mode.
.text
.globl EXT(strlcpy)
.align 5
-LEXT(strlcpy)
- andi. r0,r4,3 // is source aligned?
- dcbt 0,r4 // touch in source
- lis r6,hi16(0xFEFEFEFF) // start to load magic constants
+LEXT(strlcpy) // size_t strlcpy(char *dst, const char *src, size_t size);
+ andi. r0,r4,GPR_BYTES-1 // is source aligned?
+#if defined(__ppc__)
+ lis r6,hi16(0xFEFEFEFF) // start to generate 32-bit magic constants
lis r7,hi16(0x80808080)
- dcbtst 0,r3 // touch in dst
ori r6,r6,lo16(0xFEFEFEFF)
ori r7,r7,lo16(0x80808080)
- mr r9,r3 // use r9 for dest ptr (r3 remembers dst start)
+#else
+ ld r6,_COMM_PAGE_MAGIC_FE(0) // get 0xFEFEFEFE FEFEFEFF from commpage
+ ld r7,_COMM_PAGE_MAGIC_80(0) // get 0x80808080 80808080 from commpage
+#endif
+ mr r9,r3 // use r9 for dest ptr (must return r3 intact)
beq Laligned // source is aligned
- subfic r0,r0,4 // r0 <- #bytes to word align source
+ subfic r0,r0,GPR_BYTES // r0 <- #bytes to align source
// Copy min(r0,r5) bytes, until 0-byte found.
// r0 = #bytes we propose to copy (NOTE: must be >0)
beq cr1,L0found // byte was 0
bne Lbyteloop // r0!=0, source not yet aligned
-// Source is word aligned. Loop over words until end of buffer. We align
-// the source, rather than the dest, to avoid getting spurious page faults.
-// r4 = source ptr (word aligned)
+// Source is aligned. Loop over words or doublewords until end of buffer. We
+// align the source, rather than the dest, to avoid getting spurious page faults.
+// r4 = source ptr (aligned)
// r5 = length remaining in buffer
// r6 = 0xFEFEFEFF
// r7 = 0x80808080
// r9 = dest ptr (unaligned)
Laligned:
- srwi. r8,r5,2 // get #words in buffer
+ srgi. r8,r5,LOG2_GPR_BYTES// get #words or doublewords in buffer
addi r0,r5,1 // if no words, compare rest of buffer
- beq Lbyteloop // r8==0, no words
+ beq-- Lbyteloop // r8==0, no words
mtctr r8 // set up word loop count
- rlwinm r5,r5,0,0x3 // mask buffer length down to leftover bytes
+ rlwinm r5,r5,0,GPR_BYTES-1 // mask buffer length down to leftover bytes
b LwordloopEnter
-// Move a word at a time, until one of two conditions:
+// Move a word or doubleword at a time, until one of two conditions:
// - a zero byte is found
// - end of buffer
// At this point, registers are as follows:
-// r4 = source ptr (word aligned)
-// r5 = leftover bytes in buffer (0..3)
+// r4 = source ptr (aligned)
+// r5 = leftover bytes in buffer (0..GPR_BYTES-1)
// r6 = 0xFEFEFEFF
// r7 = 0x80808080
// r9 = dest ptr (unaligned)
-// ctr = whole words left in buffer
+// ctr = whole words or doublewords left in buffer
.align 5 // align inner loop, which is 8 words long
Lwordloop:
- stw r8,0(r9) // pack word into destination
- addi r9,r9,4
+ stg r8,0(r9) // pack word or doubleword into destination
+ addi r9,r9,GPR_BYTES
LwordloopEnter:
- lwz r8,0(r4) // r8 <- next 4 source bytes
- addi r4,r4,4
+ lg r8,0(r4) // r8 <- next 4 or 8 source bytes
+ addi r4,r4,GPR_BYTES
add r10,r8,r6 // r10 <- word + 0xFEFEFEFF
andc r12,r7,r8 // r12 <- ~word & 0x80808080
and. r11,r10,r12 // r11 <- nonzero iff word has a 0-byte
beq Lleftovers // 0-byte not found in aligned words
// Found a 0-byte. Store last word up to and including the 0, a byte at a time.
-// r8 = last word, known to have a 0-byte
+// r8 = last word or doubleword, known to have a 0-byte
// r9 = dest ptr
Lstorelastbytes:
- srwi. r0,r8,24 // right justify next byte and test for 0
- slwi r8,r8,8 // shift next byte into position
+ srgi. r0,r8,GPR_BYTES*8-8 // right justify next byte and test for 0
+ slgi r8,r8,8 // shift next byte into position
stb r0,0(r9) // pack into dest
addi r9,r9,1
bne Lstorelastbytes // loop until 0 stored
subi r3,r3,1 // don't count the 0
blr // return strlen(src)
-// 0-byte not found in aligned source words. There are up to 3 leftover source
-// bytes, hopefully the 0-byte is among them.
-// r4 = source ptr (word aligned)
-// r5 = leftover bytes in buffer (0..3)
+// 0-byte not found in aligned source words. There are up to GPR_BYTES-1 leftover
+// source bytes, hopefully the 0-byte is among them.
+// r4 = source ptr (aligned)
+// r5 = leftover bytes in buffer (0..GPR_BYTES-1)
// r6 = 0xFEFEFEFF
// r7 = 0x80808080
-// r8 = last full word of source
+// r8 = last full word or doubleword of source
// r9 = dest ptr (unaligned)
Lleftovers:
- stw r8,0(r9) // store last word
- addi r9,r9,4
- addi r0,r5,1 // make sure r5 terminate byte loop (not r0)
+ stg r8,0(r9) // store last word or doubleword
+ addi r9,r9,GPR_BYTES
+ addi r0,r5,1 // make sure r5 terminates byte loop (not r0)
b Lbyteloop
// Buffer full but 0-byte not found. Stuff a 0 into last byte of buffer.
projects / apple / libc.git / blobdiff