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--- Libc/Libc-320/ppc/string/strncmp.s
+++ Libc/Libc-391/ppc/string/strncmp.s
@@ -2,8 +2,6 @@
* Copyright (c) 2002 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
@@ -26,6 +24,17 @@
#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 N C M P *
// *****************
@@ -46,70 +55,76 @@
// 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 routine is doubleword parallel in 64-bit mode.
.text
.globl EXT(strncmp)
.align 5
-LEXT(strncmp) // int strncmp(const char *s1,const char *s2,size_t len);
- cmplwi cr1,r5,8 // is buffer too short to bother with word compares?
- andi. r0,r3,3 // is LHS aligned?
- dcbt 0,r3 // touch in LHS
- subi r3,r3,4 // we use "lwzu" in the word inner loop
- subi r4,r4,4
+LEXT(strncmp) // int strncmp(const char *s1,const char *s2,size_t len);
+ cmplgi cr1,r5,GPR_BYTES*2 // buffer too short to bother? (WARNING: cr1 is used later)
+ andi. r0,r3,GPR_BYTES-1 // is LHS aligned?
+ subi r3,r3,GPR_BYTES // we use "lgu" in the inner loops
+ subi r4,r4,GPR_BYTES
blt cr1,Lshort // short buffer, just compare a byte at a time
- lis r2,hi16(0xFEFEFEFF) // start to load magic constants
+#if defined(__ppc__)
+ lis r2,hi16(0xFEFEFEFF) // start to generate 32-bit magic constants
lis r6,hi16(0x80808080)
ori r2,r2,lo16(0xFEFEFEFF)
ori r6,r6,lo16(0x80808080)
+#else
+ ld r2,_COMM_PAGE_MAGIC_FE(0) // get 0xFEFEFEFE FEFEFEFF from commpage
+ ld r6,_COMM_PAGE_MAGIC_80(0) // get 0x80808080 80808080 from commpage
+#endif
beq Laligned // LHS is aligned
- subfic r0,r0,4 // r0 <- #bytes to word align LHS
- mtctr r0 // set up for byte loop
- sub r5,r5,r0 // adjust length
+ subfic r0,r0,GPR_BYTES // r0 <- #bytes to align LHS
+ mtctr r0
+ sub r5,r5,r0 // adjust length
b Lbyteloop
// Handle short operands or end-of-buffer.
-// r3 = LHS ptr - 4 (unaligned)
-// r4 = RHS ptr - 4 (unaligned)
-// r5 = length remaining in buffer (0..7)
+// r3 = LHS ptr - GPR_BYTES (unaligned)
+// r4 = RHS ptr - GPR_BYTES (unaligned)
+// r5 = length remaining in buffer (0..GPR_BYTES*2-1)
// cr1 = blt set
Lshort:
- cmpwi r5,0 // buffer null?
+ cmpgi r5,0 // buffer null?
mtctr r5 // assume not null, set up for loop
bne Lbyteloop // buffer not null
li r3,0 // if buffer null, say "equal"
blr
-// We're at a RHS page boundary. Compare 4 bytes in order to cross the page
+// We're at a RHS page boundary. Compare GPR_BYTES bytes in order to cross the page
// but still keep the LHS ptr word-aligned.
// r2 = 0xFEFEFEFF
-// r3 = LHS ptr - 4 (aligned)
-// r4 = RHS ptr - 4 (unaligned)
+// r3 = LHS ptr - GPR_BYTES (aligned)
+// r4 = RHS ptr - GPR_BYTES (unaligned)
// r5 = length remaining in buffer (may be 0)
// r6 = 0x80808080
Lcrosspage:
- cmplwi cr1,r5,8 // not enough left in buffer for word compares?
- li r0,4 // get #bytes to cross RHS page
+ cmplgi cr1,r5,GPR_BYTES*2 // not enough left in buffer for word compares?
+ li r0,GPR_BYTES // get #bytes to cross RHS page
blt cr1,Lshort // buffer is about to end
- mtctr r0 // set up to compare 4 bytes
+ mtctr r0 // set up to compare GPR_BYTES bytes
sub r5,r5,r0 // adjust length
b Lbyteloop
// Compare bytes, until 0-byte or difference found.
// r2 = 0xFEFEFEFF (if cr1 bge)
-// r3 = LHS ptr - 4 (unaligned)
-// r4 = RHS ptr - 4 (unaligned)
+// r3 = LHS ptr - GPR_BYTES (unaligned)
+// r4 = RHS ptr - GPR_BYTES (unaligned)
// r5 = length remaining in buffer (may be 0)
// r6 = 0x80808080 (if cr1 bge)
// cr1 = blt if this is end of buffer
.align 5 // align inner loop, which is 8 words long
Lbyteloop:
- lbz r7,4(r3) // next LHS byte
+ lbz r7,GPR_BYTES(r3) // next LHS byte
addi r3,r3,1
- lbz r8,4(r4) // next RHS byte
+ lbz r8,GPR_BYTES(r4) // next RHS byte
addi r4,r4,1
cmpwi cr0,r7,0 // zero?
cmpw cr7,r7,r8 // equal?
@@ -119,46 +134,46 @@
bne Ldifferent // done if bytes differ or are 0
blt cr1,Ldifferent // done if buffer end (ie, if r5==0)
-// LHS is now word aligned. Loop over words until end of RHS page or buffer.
-// When we get to the end of the page, we compare 4 bytes, so that we keep
-// the LHS word aligned.
+// LHS is now aligned. Loop over words or doublewords until end of RHS page
+// or buffer. When we get to the end of the page, we compare GPR_BYTES bytes,
+// so that we keep the LHS aligned.
// r2 = 0xFEFEFEFF
-// r3 = LHS ptr - 4 (aligned)
-// r4 = RHS ptr - 4 (unaligned)
+// r3 = LHS ptr - GPR_BYTES (aligned)
+// r4 = RHS ptr - GPR_BYTES (unaligned)
// r5 = length remaining in buffer (may be 0)
// r6 = 0x80808080
Laligned:
- addi r9,r4,4 // restore true address of next RHS byte
+ addi r9,r4,GPR_BYTES // restore true address of next RHS byte
rlwinm r9,r9,0,0xFFF // get RHS offset in page
subfic r0,r9,4096 // get #bytes left in RHS page
subfc r7,r0,r5 // ***
subfe r8,r5,r5 // * r9 <- min(r0,r5),
and r7,r7,r8 // * using algorithm in Compiler Writer's Guide
add r9,r0,r7 // ***
- srwi. r8,r9,2 // get #words we can compare
- beq-- Lcrosspage // no words so advance to next RHS page
- slwi r9,r8,2 // convert #words to #bytes
+ srgi. r8,r9,LOG2_GPR_BYTES// get #words or doublewords we can compare
+ beq-- Lcrosspage // none so advance to next RHS page
+ slgi r9,r8,LOG2_GPR_BYTES// get #bytes we will be comparing in parallel loop
mtctr r8 // set up loop count
sub r5,r5,r9 // decrement length remaining
b Lwordloop
-// Inner loop: compare a word at a time, until one of three conditions:
+// Inner loop: compare a word or doubleword at a time, until one of three conditions:
// - a difference is found
// - a zero byte is found
// - end of count (ie, end of buffer or RHS page, whichever is first)
// At this point, registers are as follows:
// r2 = 0xFEFEFEFF
-// r3 = LHS ptr - 4 (aligned)
-// r4 = RHS ptr - 4 (unaligned)
+// r3 = LHS ptr - GPR_BYTES (aligned)
+// r4 = RHS ptr - GPR_BYTES (unaligned)
// r5 = length remaining in buffer (may be 0)
// r6 = 0x80808080
-// ctr = count of words until end of buffer or RHS page
+// ctr = count of words or doublewords until end of buffer or RHS page
.align 5 // align inner loop, which is 8 words long
Lwordloop:
- lwzu r7,4(r3) // r7 <- next 4 LHS bytes
- lwzu r8,4(r4) // r8 <- next 4 RHS bytes
+ lgu r7,GPR_BYTES(r3) // r7 <- next 4 or 8 LHS bytes
+ lgu r8,GPR_BYTES(r4) // r8 <- next 4 or 8 RHS bytes
add r10,r7,r2 // r10 <- LHS + 0xFEFEFEFF
andc r12,r6,r7 // r12 <- ~LHS & 0x80808080
xor r11,r7,r8 // r11 <- compare the words
@@ -173,14 +188,19 @@
// false hits in the 0-byte test, which consist of 0x01 bytes that preceed
// the 0-byte.
- slwi r0,r7,7 // move 0x01 bits in LHS into position 0x80
+ slgi r0,r7,7 // move 0x01 bits in LHS into position 0x80
andc r9,r9,r0 // mask out the false 0-hits from 0x01 bytes
or r11,r11,r9 // recompute difference vector
- cntlzw r0,r11 // find 1st difference (r0 = 0..31)
- rlwinm r9,r0,0,0x18 // byte align bit offset (r9 = 0,8,16, or 24)
+ cntlzg r0,r11 // find 1st difference (r0 = 0..31 or 63)
+ rlwinm r9,r0,0,0x38 // byte align bit offset (r9 = 0,8,16, or 24)
addi r0,r9,8 // now, r0 = 8, 16, 24, or 32
+#if defined(__ppc__)
rlwnm r7,r7,r0,24,31 // right justify differing bytes and mask off rest
rlwnm r8,r8,r0,24,31
+#else
+ rldcl r7,r7,r0,56 // right justify differing bytes and mask off rest
+ rldcl r8,r8,r0,56
+#endif
Ldifferent: // bytes in r7 and r8 differ or are 0
sub r3,r7,r8 // compute return value