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Diffstat (limited to 'arch/sh/lib64/udivdi3.S')
-rw-r--r-- | arch/sh/lib64/udivdi3.S | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/arch/sh/lib64/udivdi3.S b/arch/sh/lib64/udivdi3.S deleted file mode 100644 index c032cb157589..000000000000 --- a/arch/sh/lib64/udivdi3.S +++ /dev/null @@ -1,121 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - .section .text..SHmedia32,"ax" - .align 2 - .global __udivdi3 -__udivdi3: - shlri r3,1,r4 - nsb r4,r22 - shlld r3,r22,r6 - shlri r6,49,r5 - movi 0xffffffffffffbaf1,r21 /* .l shift count 17. */ - sub r21,r5,r1 - mmulfx.w r1,r1,r4 - mshflo.w r1,r63,r1 - sub r63,r22,r20 // r63 == 64 % 64 - mmulfx.w r5,r4,r4 - pta large_divisor,tr0 - addi r20,32,r9 - msub.w r1,r4,r1 - madd.w r1,r1,r1 - mmulfx.w r1,r1,r4 - shlri r6,32,r7 - bgt/u r9,r63,tr0 // large_divisor - mmulfx.w r5,r4,r4 - shlri r2,32+14,r19 - addi r22,-31,r0 - msub.w r1,r4,r1 - - mulu.l r1,r7,r4 - addi r1,-3,r5 - mulu.l r5,r19,r5 - sub r63,r4,r4 // Negate to make sure r1 ends up <= 1/r2 - shlri r4,2,r4 /* chop off leading %0000000000000000 001.00000000000 - or, as - the case may be, %0000000000000000 000.11111111111, still */ - muls.l r1,r4,r4 /* leaving at least one sign bit. */ - mulu.l r5,r3,r8 - mshalds.l r1,r21,r1 - shari r4,26,r4 - shlld r8,r0,r8 - add r1,r4,r1 // 31 bit unsigned reciprocal now in r1 (msb equiv. 0.5) - sub r2,r8,r2 - /* Can do second step of 64 : 32 div now, using r1 and the rest in r2. */ - - shlri r2,22,r21 - mulu.l r21,r1,r21 - shlld r5,r0,r8 - addi r20,30-22,r0 - shlrd r21,r0,r21 - mulu.l r21,r3,r5 - add r8,r21,r8 - mcmpgt.l r21,r63,r21 // See Note 1 - addi r20,30,r0 - mshfhi.l r63,r21,r21 - sub r2,r5,r2 - andc r2,r21,r2 - - /* small divisor: need a third divide step */ - mulu.l r2,r1,r7 - ptabs r18,tr0 - addi r2,1,r2 - shlrd r7,r0,r7 - mulu.l r7,r3,r5 - add r8,r7,r8 - sub r2,r3,r2 - cmpgt r2,r5,r5 - add r8,r5,r2 - /* could test r3 here to check for divide by zero. */ - blink tr0,r63 - -large_divisor: - mmulfx.w r5,r4,r4 - shlrd r2,r9,r25 - shlri r25,32,r8 - msub.w r1,r4,r1 - - mulu.l r1,r7,r4 - addi r1,-3,r5 - mulu.l r5,r8,r5 - sub r63,r4,r4 // Negate to make sure r1 ends up <= 1/r2 - shlri r4,2,r4 /* chop off leading %0000000000000000 001.00000000000 - or, as - the case may be, %0000000000000000 000.11111111111, still */ - muls.l r1,r4,r4 /* leaving at least one sign bit. */ - shlri r5,14-1,r8 - mulu.l r8,r7,r5 - mshalds.l r1,r21,r1 - shari r4,26,r4 - add r1,r4,r1 // 31 bit unsigned reciprocal now in r1 (msb equiv. 0.5) - sub r25,r5,r25 - /* Can do second step of 64 : 32 div now, using r1 and the rest in r25. */ - - shlri r25,22,r21 - mulu.l r21,r1,r21 - pta no_lo_adj,tr0 - addi r22,32,r0 - shlri r21,40,r21 - mulu.l r21,r7,r5 - add r8,r21,r8 - shlld r2,r0,r2 - sub r25,r5,r25 - bgtu/u r7,r25,tr0 // no_lo_adj - addi r8,1,r8 - sub r25,r7,r25 -no_lo_adj: - mextr4 r2,r25,r2 - - /* large_divisor: only needs a few adjustments. */ - mulu.l r8,r6,r5 - ptabs r18,tr0 - /* bubble */ - cmpgtu r5,r2,r5 - sub r8,r5,r2 - blink tr0,r63 - -/* Note 1: To shift the result of the second divide stage so that the result - always fits into 32 bits, yet we still reduce the rest sufficiently - would require a lot of instructions to do the shifts just right. Using - the full 64 bit shift result to multiply with the divisor would require - four extra instructions for the upper 32 bits (shift / mulu / shift / sub). - Fortunately, if the upper 32 bits of the shift result are nonzero, we - know that the rest after taking this partial result into account will - fit into 32 bits. So we just clear the upper 32 bits of the rest if the - upper 32 bits of the partial result are nonzero. */ |