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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4358 | Serge | 1 | // |
| 2 | // DIV U32 |
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| 3 | // |
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| 4 | // UNR recurrence (q = a / b): |
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| 5 | // look for z such that 2^32 - b <= b * z < 2^32 |
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| 6 | // then q - 1 <= (a * z) / 2^32 <= q |
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| 7 | // |
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| 8 | // INPUT: $r0: dividend, $r1: divisor |
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| 9 | // OUTPUT: $r0: result, $r1: modulus |
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| 10 | // CLOBBER: $r2 - $r3, $p0 - $p1 |
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| 11 | // SIZE: 22 / 14 * 8 bytes |
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| 12 | // |
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| 13 | bfind u32 $r2 $r1 |
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| 14 | xor b32 $r2 $r2 0x1f |
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| 15 | mov b32 $r3 0x1 |
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| 16 | shl b32 $r2 $r3 clamp $r2 |
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| 17 | cvt u32 $r1 neg u32 $r1 |
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| 18 | mul $r3 u32 $r1 u32 $r2 |
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| 19 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 20 | mul $r3 u32 $r1 u32 $r2 |
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| 21 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 22 | mul $r3 u32 $r1 u32 $r2 |
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| 23 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 24 | mul $r3 u32 $r1 u32 $r2 |
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| 25 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 26 | mul $r3 u32 $r1 u32 $r2 |
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| 27 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 28 | mov b32 $r3 $r0 |
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| 29 | mul high $r0 u32 $r0 u32 $r2 |
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| 30 | cvt u32 $r2 neg u32 $r1 |
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| 31 | add $r1 (mul u32 $r1 u32 $r0) $r3 |
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| 32 | set $p0 0x1 ge u32 $r1 $r2 |
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| 33 | $p0 sub b32 $r1 $r1 $r2 |
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| 34 | $p0 add b32 $r0 $r0 0x1 |
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| 35 | $p0 set $p0 0x1 ge u32 $r1 $r2 |
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| 36 | $p0 sub b32 $r1 $r1 $r2 |
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| 37 | $p0 add b32 $r0 $r0 0x1 |
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| 38 | ret |
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| 39 | // |
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| 40 | // DIV S32, like DIV U32 after taking ABS(inputs) |
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| 41 | // |
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| 42 | // INPUT: $r0: dividend, $r1: divisor |
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| 43 | // OUTPUT: $r0: result, $r1: modulus |
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| 44 | // CLOBBER: $r2 - $r3, $p0 - $p3 |
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| 45 | // |
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| 46 | set $p2 0x1 lt s32 $r0 0x0 |
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| 47 | set $p3 0x1 lt s32 $r1 0x0 xor $p2 |
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| 48 | cvt s32 $r0 abs s32 $r0 |
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| 49 | cvt s32 $r1 abs s32 $r1 |
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| 50 | bfind u32 $r2 $r1 |
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| 51 | xor b32 $r2 $r2 0x1f |
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| 52 | mov b32 $r3 0x1 |
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| 53 | shl b32 $r2 $r3 clamp $r2 |
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| 54 | cvt u32 $r1 neg u32 $r1 |
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| 55 | mul $r3 u32 $r1 u32 $r2 |
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| 56 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 57 | mul $r3 u32 $r1 u32 $r2 |
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| 58 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 59 | mul $r3 u32 $r1 u32 $r2 |
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| 60 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 61 | mul $r3 u32 $r1 u32 $r2 |
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| 62 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 63 | mul $r3 u32 $r1 u32 $r2 |
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| 64 | add $r2 (mul high u32 $r2 u32 $r3) $r2 |
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| 65 | mov b32 $r3 $r0 |
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| 66 | mul high $r0 u32 $r0 u32 $r2 |
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| 67 | cvt u32 $r2 neg u32 $r1 |
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| 68 | add $r1 (mul u32 $r1 u32 $r0) $r3 |
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| 69 | set $p0 0x1 ge u32 $r1 $r2 |
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| 70 | $p0 sub b32 $r1 $r1 $r2 |
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| 71 | $p0 add b32 $r0 $r0 0x1 |
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| 72 | $p0 set $p0 0x1 ge u32 $r1 $r2 |
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| 73 | $p0 sub b32 $r1 $r1 $r2 |
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| 74 | $p0 add b32 $r0 $r0 0x1 |
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| 75 | $p3 cvt s32 $r0 neg s32 $r0 |
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| 76 | $p2 cvt s32 $r1 neg s32 $r1 |
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| 77 | ret |
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| 78 | // |
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| 79 | // RCP F64: Newton Raphson reciprocal(x): r_{i+1} = r_i * (2.0 - x * r_i) |
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| 80 | // |
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| 81 | // INPUT: $r0d (x) |
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| 82 | // OUTPUT: $r0d (rcp(x)) |
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| 83 | // CLOBBER: $r2 - $r7 |
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| 84 | // SIZE: 9 * 8 bytes |
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| 85 | // |
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| 86 | nop |
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| 87 | ret |
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| 88 | // RSQ F64: Newton Raphson rsqrt(x): r_{i+1} = r_i * (1.5 - 0.5 * x * r_i * r_i) |
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| 89 | // |
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| 90 | // INPUT: $r0d (x) |
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| 91 | // OUTPUT: $r0d (rsqrt(x)) |
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| 92 | // CLOBBER: $r2 - $r7 |
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| 93 | // SIZE: 14 * 8 bytes |
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| 94 | // |
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| 95 | nop |
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| 96 | ret |