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Diffstat (limited to 'third_party/git/ppc/sha1ppc.S')
| -rw-r--r-- | third_party/git/ppc/sha1ppc.S | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/third_party/git/ppc/sha1ppc.S b/third_party/git/ppc/sha1ppc.S deleted file mode 100644 index 1711eef6e7..0000000000 --- a/third_party/git/ppc/sha1ppc.S +++ /dev/null @@ -1,224 +0,0 @@ -/* - * SHA-1 implementation for PowerPC. - * - * Copyright (C) 2005 Paul Mackerras <paulus@samba.org> - */ - -/* - * PowerPC calling convention: - * %r0 - volatile temp - * %r1 - stack pointer. - * %r2 - reserved - * %r3-%r12 - Incoming arguments & return values; volatile. - * %r13-%r31 - Callee-save registers - * %lr - Return address, volatile - * %ctr - volatile - * - * Register usage in this routine: - * %r0 - temp - * %r3 - argument (pointer to 5 words of SHA state) - * %r4 - argument (pointer to data to hash) - * %r5 - Constant K in SHA round (initially number of blocks to hash) - * %r6-%r10 - Working copies of SHA variables A..E (actually E..A order) - * %r11-%r26 - Data being hashed W[]. - * %r27-%r31 - Previous copies of A..E, for final add back. - * %ctr - loop count - */ - - -/* - * We roll the registers for A, B, C, D, E around on each - * iteration; E on iteration t is D on iteration t+1, and so on. - * We use registers 6 - 10 for this. (Registers 27 - 31 hold - * the previous values.) - */ -#define RA(t) (((t)+4)%5+6) -#define RB(t) (((t)+3)%5+6) -#define RC(t) (((t)+2)%5+6) -#define RD(t) (((t)+1)%5+6) -#define RE(t) (((t)+0)%5+6) - -/* We use registers 11 - 26 for the W values */ -#define W(t) ((t)%16+11) - -/* Register 5 is used for the constant k */ - -/* - * The basic SHA-1 round function is: - * E += ROTL(A,5) + F(B,C,D) + W[i] + K; B = ROTL(B,30) - * Then the variables are renamed: (A,B,C,D,E) = (E,A,B,C,D). - * - * Every 20 rounds, the function F() and the constant K changes: - * - 20 rounds of f0(b,c,d) = "bit wise b ? c : d" = (^b & d) + (b & c) - * - 20 rounds of f1(b,c,d) = b^c^d = (b^d)^c - * - 20 rounds of f2(b,c,d) = majority(b,c,d) = (b&d) + ((b^d)&c) - * - 20 more rounds of f1(b,c,d) - * - * These are all scheduled for near-optimal performance on a G4. - * The G4 is a 3-issue out-of-order machine with 3 ALUs, but it can only - * *consider* starting the oldest 3 instructions per cycle. So to get - * maximum performance out of it, you have to treat it as an in-order - * machine. Which means interleaving the computation round t with the - * computation of W[t+4]. - * - * The first 16 rounds use W values loaded directly from memory, while the - * remaining 64 use values computed from those first 16. We preload - * 4 values before starting, so there are three kinds of rounds: - * - The first 12 (all f0) also load the W values from memory. - * - The next 64 compute W(i+4) in parallel. 8*f0, 20*f1, 20*f2, 16*f1. - * - The last 4 (all f1) do not do anything with W. - * - * Therefore, we have 6 different round functions: - * STEPD0_LOAD(t,s) - Perform round t and load W(s). s < 16 - * STEPD0_UPDATE(t,s) - Perform round t and compute W(s). s >= 16. - * STEPD1_UPDATE(t,s) - * STEPD2_UPDATE(t,s) - * STEPD1(t) - Perform round t with no load or update. - * - * The G5 is more fully out-of-order, and can find the parallelism - * by itself. The big limit is that it has a 2-cycle ALU latency, so - * even though it's 2-way, the code has to be scheduled as if it's - * 4-way, which can be a limit. To help it, we try to schedule the - * read of RA(t) as late as possible so it doesn't stall waiting for - * the previous round's RE(t-1), and we try to rotate RB(t) as early - * as possible while reading RC(t) (= RB(t-1)) as late as possible. - */ - -/* the initial loads. */ -#define LOADW(s) \ - lwz W(s),(s)*4(%r4) - -/* - * Perform a step with F0, and load W(s). Uses W(s) as a temporary - * before loading it. - * This is actually 10 instructions, which is an awkward fit. - * It can execute grouped as listed, or delayed one instruction. - * (If delayed two instructions, there is a stall before the start of the - * second line.) Thus, two iterations take 7 cycles, 3.5 cycles per round. - */ -#define STEPD0_LOAD(t,s) \ -add RE(t),RE(t),W(t); andc %r0,RD(t),RB(t); and W(s),RC(t),RB(t); \ -add RE(t),RE(t),%r0; rotlwi %r0,RA(t),5; rotlwi RB(t),RB(t),30; \ -add RE(t),RE(t),W(s); add %r0,%r0,%r5; lwz W(s),(s)*4(%r4); \ -add RE(t),RE(t),%r0 - -/* - * This is likewise awkward, 13 instructions. However, it can also - * execute starting with 2 out of 3 possible moduli, so it does 2 rounds - * in 9 cycles, 4.5 cycles/round. - */ -#define STEPD0_UPDATE(t,s,loadk...) \ -add RE(t),RE(t),W(t); andc %r0,RD(t),RB(t); xor W(s),W((s)-16),W((s)-3); \ -add RE(t),RE(t),%r0; and %r0,RC(t),RB(t); xor W(s),W(s),W((s)-8); \ -add RE(t),RE(t),%r0; rotlwi %r0,RA(t),5; xor W(s),W(s),W((s)-14); \ -add RE(t),RE(t),%r5; loadk; rotlwi RB(t),RB(t),30; rotlwi W(s),W(s),1; \ -add RE(t),RE(t),%r0 - -/* Nicely optimal. Conveniently, also the most common. */ -#define STEPD1_UPDATE(t,s,loadk...) \ -add RE(t),RE(t),W(t); xor %r0,RD(t),RB(t); xor W(s),W((s)-16),W((s)-3); \ -add RE(t),RE(t),%r5; loadk; xor %r0,%r0,RC(t); xor W(s),W(s),W((s)-8); \ -add RE(t),RE(t),%r0; rotlwi %r0,RA(t),5; xor W(s),W(s),W((s)-14); \ -add RE(t),RE(t),%r0; rotlwi RB(t),RB(t),30; rotlwi W(s),W(s),1 - -/* - * The naked version, no UPDATE, for the last 4 rounds. 3 cycles per. - * We could use W(s) as a temp register, but we don't need it. - */ -#define STEPD1(t) \ - add RE(t),RE(t),W(t); xor %r0,RD(t),RB(t); \ -rotlwi RB(t),RB(t),30; add RE(t),RE(t),%r5; xor %r0,%r0,RC(t); \ -add RE(t),RE(t),%r0; rotlwi %r0,RA(t),5; /* spare slot */ \ -add RE(t),RE(t),%r0 - -/* - * 14 instructions, 5 cycles per. The majority function is a bit - * awkward to compute. This can execute with a 1-instruction delay, - * but it causes a 2-instruction delay, which triggers a stall. - */ -#define STEPD2_UPDATE(t,s,loadk...) \ -add RE(t),RE(t),W(t); and %r0,RD(t),RB(t); xor W(s),W((s)-16),W((s)-3); \ -add RE(t),RE(t),%r0; xor %r0,RD(t),RB(t); xor W(s),W(s),W((s)-8); \ -add RE(t),RE(t),%r5; loadk; and %r0,%r0,RC(t); xor W(s),W(s),W((s)-14); \ -add RE(t),RE(t),%r0; rotlwi %r0,RA(t),5; rotlwi W(s),W(s),1; \ -add RE(t),RE(t),%r0; rotlwi RB(t),RB(t),30 - -#define STEP0_LOAD4(t,s) \ - STEPD0_LOAD(t,s); \ - STEPD0_LOAD((t+1),(s)+1); \ - STEPD0_LOAD((t)+2,(s)+2); \ - STEPD0_LOAD((t)+3,(s)+3) - -#define STEPUP4(fn, t, s, loadk...) \ - STEP##fn##_UPDATE(t,s,); \ - STEP##fn##_UPDATE((t)+1,(s)+1,); \ - STEP##fn##_UPDATE((t)+2,(s)+2,); \ - STEP##fn##_UPDATE((t)+3,(s)+3,loadk) - -#define STEPUP20(fn, t, s, loadk...) \ - STEPUP4(fn, t, s,); \ - STEPUP4(fn, (t)+4, (s)+4,); \ - STEPUP4(fn, (t)+8, (s)+8,); \ - STEPUP4(fn, (t)+12, (s)+12,); \ - STEPUP4(fn, (t)+16, (s)+16, loadk) - - .globl ppc_sha1_core -ppc_sha1_core: - stwu %r1,-80(%r1) - stmw %r13,4(%r1) - - /* Load up A - E */ - lmw %r27,0(%r3) - - mtctr %r5 - -1: - LOADW(0) - lis %r5,0x5a82 - mr RE(0),%r31 - LOADW(1) - mr RD(0),%r30 - mr RC(0),%r29 - LOADW(2) - ori %r5,%r5,0x7999 /* K0-19 */ - mr RB(0),%r28 - LOADW(3) - mr RA(0),%r27 - - STEP0_LOAD4(0, 4) - STEP0_LOAD4(4, 8) - STEP0_LOAD4(8, 12) - STEPUP4(D0, 12, 16,) - STEPUP4(D0, 16, 20, lis %r5,0x6ed9) - - ori %r5,%r5,0xeba1 /* K20-39 */ - STEPUP20(D1, 20, 24, lis %r5,0x8f1b) - - ori %r5,%r5,0xbcdc /* K40-59 */ - STEPUP20(D2, 40, 44, lis %r5,0xca62) - - ori %r5,%r5,0xc1d6 /* K60-79 */ - STEPUP4(D1, 60, 64,) - STEPUP4(D1, 64, 68,) - STEPUP4(D1, 68, 72,) - STEPUP4(D1, 72, 76,) - addi %r4,%r4,64 - STEPD1(76) - STEPD1(77) - STEPD1(78) - STEPD1(79) - - /* Add results to original values */ - add %r31,%r31,RE(0) - add %r30,%r30,RD(0) - add %r29,%r29,RC(0) - add %r28,%r28,RB(0) - add %r27,%r27,RA(0) - - bdnz 1b - - /* Save final hash, restore registers, and return */ - stmw %r27,0(%r3) - lmw %r13,4(%r1) - addi %r1,%r1,80 - blr |