diff options
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power7/strncmp.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power7/strncmp.S | 61 |
1 files changed, 53 insertions, 8 deletions
diff --git a/sysdeps/powerpc/powerpc64/power7/strncmp.S b/sysdeps/powerpc/powerpc64/power7/strncmp.S index 77ecad5ab1..e618b010bf 100644 --- a/sysdeps/powerpc/powerpc64/power7/strncmp.S +++ b/sysdeps/powerpc/powerpc64/power7/strncmp.S @@ -27,7 +27,7 @@ EALIGN (strncmp,5,0) CALL_MCOUNT 3 -#define rTMP r0 +#define rTMP2 r0 #define rRTN r3 #define rSTR1 r3 /* first string arg */ #define rSTR2 r4 /* second string arg */ @@ -40,6 +40,7 @@ EALIGN (strncmp,5,0) #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 nop @@ -83,12 +84,57 @@ 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) + cmpb rBITDIF, rWORD1, rWORD2 /* 0xff on equal bytes. */ + addi rNEG, rBITDIF, 1 + orc rNEG, rNEG, rBITDIF /* 0's below LS differing byte. */ + sldi rNEG, rNEG, 8 /* 1's above LS differing byte. */ + andc rWORD1, rWORD1, rNEG /* mask off MS bytes. */ + andc 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) + cmpb rBITDIF, rWORD1, rWORD2 /* 0xff on equal bytes. */ + addi rNEG, rBITDIF, 1 + orc rNEG, rNEG, rBITDIF /* 0's below LS differing byte. */ + sldi rNEG, rNEG, 8 /* 1's above LS differing byte. */ + andc rWORD1, rWORD1, rNEG /* mask off MS bytes. */ + andc 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 @@ -97,7 +143,7 @@ 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): @@ -105,7 +151,7 @@ L(equal): blr L(different): - ldu rWORD1,-8(rSTR1) + ld rWORD1,-8(rSTR1) xor. rBITDIF,rWORD1,rWORD2 sub rRTN,rWORD1,rWORD2 blt L(highbit) @@ -113,11 +159,10 @@ 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 |