diff options
Diffstat (limited to 'newlib/libc/machine/arm/strcmp.S')
| -rw-r--r-- | newlib/libc/machine/arm/strcmp.S | 103 |
1 files changed, 55 insertions, 48 deletions
diff --git a/newlib/libc/machine/arm/strcmp.S b/newlib/libc/machine/arm/strcmp.S index 0a4057e3b..f3e738776 100644 --- a/newlib/libc/machine/arm/strcmp.S +++ b/newlib/libc/machine/arm/strcmp.S @@ -55,6 +55,13 @@ #if defined (__thumb__) .thumb .thumb_func +#if !defined (__thumb2__) + /* If we have thumb1 only, we need to explictly mark the + compatibility. */ + .arch armv4t + .eabi_attribute Tag_also_compatible_with, "\006\013" /* v6-M. */ + .eabi_attribute Tag_ARM_ISA_use, 0 +#endif #endif .global strcmp .type strcmp, %function @@ -201,12 +208,12 @@ strcmp: /* Are both strings double-word aligned? */ orr ip, r0, r1 tst ip, #7 - bne do_align + bne .Ldo_align /* Fast path. */ init -doubleword_aligned: +.Ldoubleword_aligned: /* Get here when the strings to compare are double-word aligned. */ /* Compare two words in every iteration. */ @@ -221,14 +228,14 @@ doubleword_aligned: ldrd r2, r3, [r0], #8 ldrd r4, r5, [r1], #8 - magic_compare_and_branch w1=r2, w2=r4, label=return_24 - magic_compare_and_branch w1=r3, w2=r5, label=return_35 + magic_compare_and_branch w1=r2, w2=r4, label=.Lreturn_24 + magic_compare_and_branch w1=r3, w2=r5, label=.Lreturn_35 b 2b -do_align: +.Ldo_align: /* Is the first string word-aligned? */ ands ip, r0, #3 - beq word_aligned_r0 + beq .Lword_aligned_r0 /* Fast compare byte by byte until the first string is word-aligned. */ /* The offset of r0 from a word boundary is in ip. Thus, the number of bytes @@ -236,58 +243,58 @@ do_align: bic r0, r0, #3 ldr r2, [r0], #4 lsls ip, ip, #31 - beq byte2 - bcs byte3 + beq .Lbyte2 + bcs .Lbyte3 -byte1: +.Lbyte1: ldrb ip, [r1], #1 uxtb r3, r2, ror #BYTE1_OFFSET subs ip, r3, ip - bne fast_return - m_cbz reg=r3, label=fast_return + bne .Lfast_return + m_cbz reg=r3, label=.Lfast_return -byte2: +.Lbyte2: ldrb ip, [r1], #1 uxtb r3, r2, ror #BYTE2_OFFSET subs ip, r3, ip - bne fast_return - m_cbz reg=r3, label=fast_return + bne .Lfast_return + m_cbz reg=r3, label=.Lfast_return -byte3: +.Lbyte3: ldrb ip, [r1], #1 uxtb r3, r2, ror #BYTE3_OFFSET subs ip, r3, ip - bne fast_return - m_cbnz reg=r3, label=word_aligned_r0 + bne .Lfast_return + m_cbnz reg=r3, label=.Lword_aligned_r0 -fast_return: +.Lfast_return: mov r0, ip bx lr -word_aligned_r0: +.Lword_aligned_r0: init /* The first string is word-aligned. */ /* Is the second string word-aligned? */ ands ip, r1, #3 - bne strcmp_unaligned + bne .Lstrcmp_unaligned -word_aligned: +.Lword_aligned: /* The strings are word-aligned. */ /* Is the first string double-word aligned? */ tst r0, #4 - beq doubleword_aligned_r0 + beq .Ldoubleword_aligned_r0 /* If r0 is not double-word aligned yet, align it by loading and comparing the next word from each string. */ ldr r2, [r0], #4 ldr r4, [r1], #4 - magic_compare_and_branch w1=r2 w2=r4 label=return_24 + magic_compare_and_branch w1=r2 w2=r4 label=.Lreturn_24 -doubleword_aligned_r0: +.Ldoubleword_aligned_r0: /* Get here when r0 is double-word aligned. */ /* Is r1 doubleword_aligned? */ tst r1, #4 - beq doubleword_aligned + beq .Ldoubleword_aligned /* Get here when the strings to compare are word-aligned, r0 is double-word aligned, but r1 is not double-word aligned. */ @@ -305,9 +312,9 @@ doubleword_aligned_r0: /* Load the next double-word from each string and compare. */ ldrd r2, r3, [r0], #8 - magic_compare_and_branch w1=r2 w2=r5 label=return_25 + magic_compare_and_branch w1=r2 w2=r5 label=.Lreturn_25 ldrd r4, r5, [r1], #8 - magic_compare_and_branch w1=r3 w2=r4 label=return_34 + magic_compare_and_branch w1=r3 w2=r4 label=.Lreturn_34 b 3b .macro miscmp_word offsetlo offsethi @@ -331,47 +338,47 @@ doubleword_aligned_r0: and r2, r3, r6, S2LOMEM #\offsetlo it eq cmpeq r2, r5 - bne return_25 + bne .Lreturn_25 ldr r5, [r1], #4 cmp ip, #0 eor r3, r2, r3 S2HIMEM r2, r5, #\offsethi it eq cmpeq r3, r2 - bne return_32 + bne .Lreturn_32 b 7b .endm /* miscmp_word */ -strcmp_unaligned: +.Lstrcmp_unaligned: /* r0 is word-aligned, r1 is at offset ip from a word. */ /* Align r1 to the (previous) word-boundary. */ bic r1, r1, #3 /* Unaligned comparison word by word using LDRs. */ cmp ip, #2 - beq miscmp_word_16 /* If ip == 2. */ - bge miscmp_word_24 /* If ip == 3. */ + beq .Lmiscmp_word_16 /* If ip == 2. */ + bge .Lmiscmp_word_24 /* If ip == 3. */ miscmp_word offsetlo=8 offsethi=24 /* If ip == 1. */ -miscmp_word_16: miscmp_word offsetlo=16 offsethi=16 -miscmp_word_24: miscmp_word offsetlo=24 offsethi=8 +.Lmiscmp_word_16: miscmp_word offsetlo=16 offsethi=16 +.Lmiscmp_word_24: miscmp_word offsetlo=24 offsethi=8 -return_32: +.Lreturn_32: setup_return w1=r3, w2=r2 - b do_return -return_34: + b .Ldo_return +.Lreturn_34: setup_return w1=r3, w2=r4 - b do_return -return_25: + b .Ldo_return +.Lreturn_25: setup_return w1=r2, w2=r5 - b do_return -return_35: + b .Ldo_return +.Lreturn_35: setup_return w1=r3, w2=r5 - b do_return -return_24: + b .Ldo_return +.Lreturn_24: setup_return w1=r2, w2=r4 -do_return: +.Ldo_return: #ifdef __ARMEB__ mov r0, ip @@ -387,7 +394,7 @@ do_return: /* There is a zero or a different byte between r1 and r2. */ /* r0 contains a mask of all-zero bytes in r1. */ /* Using r0 and not ip here because cbz requires low register. */ - m_cbz reg=r0, label=compute_return_value + m_cbz reg=r0, label=.Lcompute_return_value clz r0, r0 /* r0 contains the number of bits on the left of the first all-zero byte in r1. */ rsb r0, r0, #24 @@ -395,7 +402,7 @@ do_return: lsr r1, r1, r0 lsr r2, r2, r0 -compute_return_value: +.Lcompute_return_value: movs r0, #1 cmp r1, r2 /* The return value is computed as follows. @@ -429,7 +436,7 @@ compute_return_value: eor r2, r0, r1 tst r2, #3 /* Strings not at same byte offset from a word boundary. */ - bne strcmp_unaligned + bne .Lstrcmp_unaligned ands r2, r0, #3 bic r0, r0, #3 bic r1, r1, #3 @@ -506,7 +513,7 @@ compute_return_value: RETURN -strcmp_unaligned: +.Lstrcmp_unaligned: #if 0 /* The assembly code below is based on the following alogrithm. */ |