| // Inferno's libkern/vlop-arm.s |
| // http://code.google.com/p/inferno-os/source/browse/libkern/vlop-arm.s |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved. |
| // Portions Copyright 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| #define UMULL(Rs,Rm,Rhi,Rlo,S) WORD $((14<<28)|(4<<21)|(S<<20)|(Rhi<<16)|(Rlo<<12)|(Rs<<8)|(9<<4)|Rm) |
| #define UMLAL(Rs,Rm,Rhi,Rlo,S) WORD $((14<<28)|(5<<21)|(S<<20)|(Rhi<<16)|(Rlo<<12)|(Rs<<8)|(9<<4)|Rm) |
| #define MUL(Rs,Rm,Rd,S) WORD $((14<<28)|(0<<21)|(S<<20)|(Rd<<16)|(Rs<<8)|(9<<4)|Rm) |
| arg=0 |
| |
| /* replaced use of R10 by R11 because the former can be the data segment base register */ |
| |
| TEXT _mulv(SB), $0 |
| MOVW 8(FP), R9 /* l0 */ |
| MOVW 4(FP), R11 /* h0 */ |
| MOVW 16(FP), R4 /* l1 */ |
| MOVW 12(FP), R5 /* h1 */ |
| UMULL(4, 9, 7, 6, 0) |
| MUL(11, 4, 8, 0) |
| ADD R8, R7 |
| MUL(9, 5, 8, 0) |
| ADD R8, R7 |
| MOVW R6, 4(R(arg)) |
| MOVW R7, 0(R(arg)) |
| RET |
| |
| /* multiply, add, and right-shift, yielding a 32-bit result, while |
| using 64-bit accuracy for the multiply -- for fast fixed-point math */ |
| TEXT _mularsv(SB), $0 |
| MOVW 4(FP), R11 /* m1 */ |
| MOVW 8(FP), R8 /* a */ |
| MOVW 12(FP), R4 /* rs */ |
| MOVW $0, R9 |
| UMLAL(0, 11, 9, 8, 0) |
| MOVW R8>>R4, R8 |
| RSB $32, R4, R4 |
| ORR R9<<R4, R8, R0 |
| RET |
| |
| Q = 0 |
| N = 1 |
| D = 2 |
| CC = 3 |
| TMP = 11 |
| |
| TEXT save<>(SB), 7, $0 |
| MOVW R(Q), 0(FP) |
| MOVW R(N), 4(FP) |
| MOVW R(D), 8(FP) |
| MOVW R(CC), 12(FP) |
| |
| MOVW R(TMP), R(Q) /* numerator */ |
| MOVW 20(FP), R(D) /* denominator */ |
| CMP $0, R(D) |
| BNE s1 |
| SWI 0 |
| /* MOVW -1(R(D)), R(TMP) /* divide by zero fault */ |
| s1: RET |
| |
| TEXT rest<>(SB), 7, $0 |
| MOVW 0(FP), R(Q) |
| MOVW 4(FP), R(N) |
| MOVW 8(FP), R(D) |
| MOVW 12(FP), R(CC) |
| /* |
| * return to caller |
| * of rest<> |
| */ |
| MOVW 0(R13), R14 |
| ADD $20, R13 |
| B (R14) |
| |
| TEXT div<>(SB), 7, $0 |
| MOVW $32, R(CC) |
| /* |
| * skip zeros 8-at-a-time |
| */ |
| e1: |
| AND.S $(0xff<<24),R(Q), R(N) |
| BNE e2 |
| SLL $8, R(Q) |
| SUB.S $8, R(CC) |
| BNE e1 |
| RET |
| e2: |
| MOVW $0, R(N) |
| |
| loop: |
| /* |
| * shift R(N||Q) left one |
| */ |
| SLL $1, R(N) |
| CMP $0, R(Q) |
| ORR.LT $1, R(N) |
| SLL $1, R(Q) |
| |
| /* |
| * compare numerator to denominator |
| * if less, subtract and set quotent bit |
| */ |
| CMP R(D), R(N) |
| ORR.HS $1, R(Q) |
| SUB.HS R(D), R(N) |
| SUB.S $1, R(CC) |
| BNE loop |
| RET |
| |
| TEXT _div(SB), 7, $16 |
| BL save<>(SB) |
| CMP $0, R(Q) |
| BGE d1 |
| RSB $0, R(Q), R(Q) |
| CMP $0, R(D) |
| BGE d2 |
| RSB $0, R(D), R(D) |
| d0: |
| BL div<>(SB) /* none/both neg */ |
| MOVW R(Q), R(TMP) |
| B out |
| d1: |
| CMP $0, R(D) |
| BGE d0 |
| RSB $0, R(D), R(D) |
| d2: |
| BL div<>(SB) /* one neg */ |
| RSB $0, R(Q), R(TMP) |
| B out |
| |
| TEXT _mod(SB), 7, $16 |
| BL save<>(SB) |
| CMP $0, R(D) |
| RSB.LT $0, R(D), R(D) |
| CMP $0, R(Q) |
| BGE m1 |
| RSB $0, R(Q), R(Q) |
| BL div<>(SB) /* neg numerator */ |
| RSB $0, R(N), R(TMP) |
| B out |
| m1: |
| BL div<>(SB) /* pos numerator */ |
| MOVW R(N), R(TMP) |
| B out |
| |
| TEXT _divu(SB), 7, $16 |
| BL save<>(SB) |
| BL div<>(SB) |
| MOVW R(Q), R(TMP) |
| B out |
| |
| TEXT _modu(SB), 7, $16 |
| BL save<>(SB) |
| BL div<>(SB) |
| MOVW R(N), R(TMP) |
| B out |
| |
| out: |
| BL rest<>(SB) |
| B out |
