* libc/machine/arm/strcmp.S: Use local labels.
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Corinna Vinschen
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925e1c8157
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@ -1,3 +1,7 @@
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2013-06-05 Joey Ye <joey.ye@arm.com>
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* libc/machine/arm/strcmp.S: Use local labels.
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2013-06-03 Joey Ye <joey.ye@arm.com>
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* libc/machine/arm/Makefile.am (MEMCPY_DEP): New define.
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@ -208,12 +208,12 @@ strcmp:
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/* Are both strings double-word aligned? */
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orr ip, r0, r1
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tst ip, #7
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bne do_align
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bne .Ldo_align
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/* Fast path. */
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init
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doubleword_aligned:
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.Ldoubleword_aligned:
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/* Get here when the strings to compare are double-word aligned. */
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/* Compare two words in every iteration. */
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@ -228,14 +228,14 @@ doubleword_aligned:
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ldrd r2, r3, [r0], #8
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ldrd r4, r5, [r1], #8
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magic_compare_and_branch w1=r2, w2=r4, label=return_24
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magic_compare_and_branch w1=r3, w2=r5, label=return_35
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magic_compare_and_branch w1=r2, w2=r4, label=.Lreturn_24
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magic_compare_and_branch w1=r3, w2=r5, label=.Lreturn_35
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b 2b
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do_align:
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.Ldo_align:
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/* Is the first string word-aligned? */
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ands ip, r0, #3
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beq word_aligned_r0
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beq .Lword_aligned_r0
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/* Fast compare byte by byte until the first string is word-aligned. */
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/* The offset of r0 from a word boundary is in ip. Thus, the number of bytes
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@ -243,58 +243,58 @@ do_align:
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bic r0, r0, #3
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ldr r2, [r0], #4
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lsls ip, ip, #31
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beq byte2
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bcs byte3
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beq .Lbyte2
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bcs .Lbyte3
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byte1:
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.Lbyte1:
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ldrb ip, [r1], #1
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uxtb r3, r2, ror #BYTE1_OFFSET
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subs ip, r3, ip
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bne fast_return
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m_cbz reg=r3, label=fast_return
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bne .Lfast_return
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m_cbz reg=r3, label=.Lfast_return
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byte2:
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.Lbyte2:
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ldrb ip, [r1], #1
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uxtb r3, r2, ror #BYTE2_OFFSET
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subs ip, r3, ip
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bne fast_return
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m_cbz reg=r3, label=fast_return
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bne .Lfast_return
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m_cbz reg=r3, label=.Lfast_return
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byte3:
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.Lbyte3:
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ldrb ip, [r1], #1
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uxtb r3, r2, ror #BYTE3_OFFSET
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subs ip, r3, ip
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bne fast_return
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m_cbnz reg=r3, label=word_aligned_r0
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bne .Lfast_return
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m_cbnz reg=r3, label=.Lword_aligned_r0
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fast_return:
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.Lfast_return:
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mov r0, ip
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bx lr
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word_aligned_r0:
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.Lword_aligned_r0:
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init
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/* The first string is word-aligned. */
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/* Is the second string word-aligned? */
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ands ip, r1, #3
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bne strcmp_unaligned
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bne .Lstrcmp_unaligned
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word_aligned:
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.Lword_aligned:
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/* The strings are word-aligned. */
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/* Is the first string double-word aligned? */
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tst r0, #4
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beq doubleword_aligned_r0
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beq .Ldoubleword_aligned_r0
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/* If r0 is not double-word aligned yet, align it by loading
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and comparing the next word from each string. */
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ldr r2, [r0], #4
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ldr r4, [r1], #4
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magic_compare_and_branch w1=r2 w2=r4 label=return_24
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magic_compare_and_branch w1=r2 w2=r4 label=.Lreturn_24
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doubleword_aligned_r0:
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.Ldoubleword_aligned_r0:
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/* Get here when r0 is double-word aligned. */
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/* Is r1 doubleword_aligned? */
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tst r1, #4
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beq doubleword_aligned
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beq .Ldoubleword_aligned
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/* Get here when the strings to compare are word-aligned,
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r0 is double-word aligned, but r1 is not double-word aligned. */
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@ -312,9 +312,9 @@ doubleword_aligned_r0:
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/* Load the next double-word from each string and compare. */
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ldrd r2, r3, [r0], #8
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magic_compare_and_branch w1=r2 w2=r5 label=return_25
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magic_compare_and_branch w1=r2 w2=r5 label=.Lreturn_25
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ldrd r4, r5, [r1], #8
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magic_compare_and_branch w1=r3 w2=r4 label=return_34
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magic_compare_and_branch w1=r3 w2=r4 label=.Lreturn_34
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b 3b
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.macro miscmp_word offsetlo offsethi
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@ -338,47 +338,47 @@ doubleword_aligned_r0:
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and r2, r3, r6, S2LOMEM #\offsetlo
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it eq
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cmpeq r2, r5
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bne return_25
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bne .Lreturn_25
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ldr r5, [r1], #4
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cmp ip, #0
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eor r3, r2, r3
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S2HIMEM r2, r5, #\offsethi
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it eq
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cmpeq r3, r2
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bne return_32
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bne .Lreturn_32
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b 7b
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.endm /* miscmp_word */
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strcmp_unaligned:
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.Lstrcmp_unaligned:
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/* r0 is word-aligned, r1 is at offset ip from a word. */
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/* Align r1 to the (previous) word-boundary. */
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bic r1, r1, #3
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/* Unaligned comparison word by word using LDRs. */
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cmp ip, #2
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beq miscmp_word_16 /* If ip == 2. */
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bge miscmp_word_24 /* If ip == 3. */
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beq .Lmiscmp_word_16 /* If ip == 2. */
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bge .Lmiscmp_word_24 /* If ip == 3. */
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miscmp_word offsetlo=8 offsethi=24 /* If ip == 1. */
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miscmp_word_16: miscmp_word offsetlo=16 offsethi=16
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miscmp_word_24: miscmp_word offsetlo=24 offsethi=8
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.Lmiscmp_word_16: miscmp_word offsetlo=16 offsethi=16
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.Lmiscmp_word_24: miscmp_word offsetlo=24 offsethi=8
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return_32:
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.Lreturn_32:
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setup_return w1=r3, w2=r2
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b do_return
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return_34:
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b .Ldo_return
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.Lreturn_34:
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setup_return w1=r3, w2=r4
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b do_return
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return_25:
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b .Ldo_return
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.Lreturn_25:
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setup_return w1=r2, w2=r5
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b do_return
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return_35:
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b .Ldo_return
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.Lreturn_35:
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setup_return w1=r3, w2=r5
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b do_return
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return_24:
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b .Ldo_return
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.Lreturn_24:
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setup_return w1=r2, w2=r4
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do_return:
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.Ldo_return:
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#ifdef __ARMEB__
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mov r0, ip
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@ -394,7 +394,7 @@ do_return:
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/* There is a zero or a different byte between r1 and r2. */
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/* r0 contains a mask of all-zero bytes in r1. */
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/* Using r0 and not ip here because cbz requires low register. */
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m_cbz reg=r0, label=compute_return_value
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m_cbz reg=r0, label=.Lcompute_return_value
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clz r0, r0
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/* r0 contains the number of bits on the left of the first all-zero byte in r1. */
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rsb r0, r0, #24
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@ -402,7 +402,7 @@ do_return:
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lsr r1, r1, r0
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lsr r2, r2, r0
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compute_return_value:
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.Lcompute_return_value:
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movs r0, #1
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cmp r1, r2
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/* The return value is computed as follows.
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@ -436,7 +436,7 @@ compute_return_value:
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eor r2, r0, r1
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tst r2, #3
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/* Strings not at same byte offset from a word boundary. */
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bne strcmp_unaligned
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bne .Lstrcmp_unaligned
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ands r2, r0, #3
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bic r0, r0, #3
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bic r1, r1, #3
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@ -513,7 +513,7 @@ compute_return_value:
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RETURN
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strcmp_unaligned:
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.Lstrcmp_unaligned:
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#if 0
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/* The assembly code below is based on the following alogrithm. */
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