diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power4/strncmp.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power4/strncmp.S | 63 |
1 files changed, 55 insertions, 8 deletions
diff --git a/sysdeps/powerpc/powerpc64/power4/strncmp.S b/sysdeps/powerpc/powerpc64/power4/strncmp.S index 1276e16a59..5d136cfa21 100644 --- a/sysdeps/powerpc/powerpc64/power4/strncmp.S +++ b/sysdeps/powerpc/powerpc64/power4/strncmp.S @@ -25,7 +25,7 @@ EALIGN (strncmp, 4, 0) CALL_MCOUNT 3 -#define rTMP r0 +#define rTMP2 r0 #define rRTN r3 #define rSTR1 r3 /* first string arg */ #define rSTR2 r4 /* second string arg */ @@ -38,6 +38,7 @@ EALIGN (strncmp, 4, 0) #define r7F7F r9 /* constant 0x7f7f7f7f7f7f7f7f */ #define rNEG r10 /* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */ #define rBITDIF r11 /* bits that differ in s1 & s2 words */ +#define rTMP r12 dcbt 0,rSTR1 or rTMP, rSTR2, rSTR1 @@ -79,12 +80,59 @@ L(g1): add rTMP, rFEFE, rWORD1 we don't compare two strings as different because of gunk beyond the end of the strings... */ +#ifdef __LITTLE_ENDIAN__ +L(endstring): + addi rTMP2, rTMP, -1 + beq cr1, L(equal) + andc rTMP2, rTMP2, rTMP + rldimi rTMP2, rTMP2, 1, 0 + and rWORD2, rWORD2, rTMP2 /* Mask off gunk. */ + and rWORD1, rWORD1, rTMP2 + cmpd cr1, rWORD1, rWORD2 + beq cr1, L(equal) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 /* must return an int. */ + ori rRTN, rRTN, 1 + blr +L(equal): + li rRTN, 0 + blr + +L(different): + ld rWORD1, -8(rSTR1) + xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */ + neg rNEG, rBITDIF + and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */ + cntlzd rNEG, rNEG /* bitcount of the bit. */ + andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */ + sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */ + sld rWORD2, rWORD2, rNEG + xor. rBITDIF, rWORD1, rWORD2 + sub rRTN, rWORD1, rWORD2 + blt- L(highbit) + sradi rRTN, rRTN, 63 + ori rRTN, rRTN, 1 + blr +L(highbit): + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 + blr + +#else L(endstring): and rTMP, r7F7F, rWORD1 beq cr1, L(equal) add rTMP, rTMP, r7F7F xor. rBITDIF, rWORD1, rWORD2 - andc rNEG, rNEG, rTMP blt- L(highbit) cntlzd rBITDIF, rBITDIF @@ -93,7 +141,7 @@ L(endstring): cmpd cr1, rNEG, rBITDIF sub rRTN, rWORD1, rWORD2 blt- cr1, L(equal) - sradi rRTN, rRTN, 63 + sradi rRTN, rRTN, 63 /* must return an int. */ ori rRTN, rRTN, 1 blr L(equal): @@ -101,7 +149,7 @@ L(equal): blr L(different): - ldu rWORD1, -8(rSTR1) + ld rWORD1, -8(rSTR1) xor. rBITDIF, rWORD1, rWORD2 sub rRTN, rWORD1, rWORD2 blt- L(highbit) @@ -109,11 +157,10 @@ L(different): ori rRTN, rRTN, 1 blr L(highbit): - srdi rWORD2, rWORD2, 56 - srdi rWORD1, rWORD1, 56 - sub rRTN, rWORD1, rWORD2 + sradi rRTN, rWORD2, 63 + ori rRTN, rRTN, 1 blr - +#endif /* Oh well. In this case, we just do a byte-by-byte comparison. */ .align 4 |