diff options
Diffstat (limited to 'src/math/log_s390x.s')
| -rw-r--r-- | src/math/log_s390x.s | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/math/log_s390x.s b/src/math/log_s390x.s new file mode 100644 index 0000000..4b514f3 --- /dev/null +++ b/src/math/log_s390x.s @@ -0,0 +1,168 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" + +// Minimax polynomial approximations +DATA ·logrodataL21<> + 0(SB)/8, $-.499999999999999778E+00 +DATA ·logrodataL21<> + 8(SB)/8, $0.333333333333343751E+00 +DATA ·logrodataL21<> + 16(SB)/8, $-.250000000001606881E+00 +DATA ·logrodataL21<> + 24(SB)/8, $0.199999999971603032E+00 +DATA ·logrodataL21<> + 32(SB)/8, $-.166666663114122038E+00 +DATA ·logrodataL21<> + 40(SB)/8, $-.125002923782692399E+00 +DATA ·logrodataL21<> + 48(SB)/8, $0.111142014580396256E+00 +DATA ·logrodataL21<> + 56(SB)/8, $0.759438932618934220E-01 +DATA ·logrodataL21<> + 64(SB)/8, $0.142857144267212549E+00 +DATA ·logrodataL21<> + 72(SB)/8, $-.993038938793590759E-01 +DATA ·logrodataL21<> + 80(SB)/8, $-1.0 +GLOBL ·logrodataL21<> + 0(SB), RODATA, $88 + +// Constants +DATA ·logxminf<> + 0(SB)/8, $0xfff0000000000000 +GLOBL ·logxminf<> + 0(SB), RODATA, $8 +DATA ·logxnan<> + 0(SB)/8, $0x7ff8000000000000 +GLOBL ·logxnan<> + 0(SB), RODATA, $8 +DATA ·logx43f<> + 0(SB)/8, $0x43f0000000000000 +GLOBL ·logx43f<> + 0(SB), RODATA, $8 +DATA ·logxl2<> + 0(SB)/8, $0x3fda7aecbeba4e46 +GLOBL ·logxl2<> + 0(SB), RODATA, $8 +DATA ·logxl1<> + 0(SB)/8, $0x3ffacde700000000 +GLOBL ·logxl1<> + 0(SB), RODATA, $8 + +/* Input transform scale and add constants */ +DATA ·logxm<> + 0(SB)/8, $0x3fc77604e63c84b1 +DATA ·logxm<> + 8(SB)/8, $0x40fb39456ab53250 +DATA ·logxm<> + 16(SB)/8, $0x3fc9ee358b945f3f +DATA ·logxm<> + 24(SB)/8, $0x40fb39418bf3b137 +DATA ·logxm<> + 32(SB)/8, $0x3fccfb2e1304f4b6 +DATA ·logxm<> + 40(SB)/8, $0x40fb393d3eda3022 +DATA ·logxm<> + 48(SB)/8, $0x3fd0000000000000 +DATA ·logxm<> + 56(SB)/8, $0x40fb393969e70000 +DATA ·logxm<> + 64(SB)/8, $0x3fd11117aafbfe04 +DATA ·logxm<> + 72(SB)/8, $0x40fb3936eaefafcf +DATA ·logxm<> + 80(SB)/8, $0x3fd2492af5e658b2 +DATA ·logxm<> + 88(SB)/8, $0x40fb39343ff01715 +DATA ·logxm<> + 96(SB)/8, $0x3fd3b50c622a43dd +DATA ·logxm<> + 104(SB)/8, $0x40fb39315adae2f3 +DATA ·logxm<> + 112(SB)/8, $0x3fd56bbeea918777 +DATA ·logxm<> + 120(SB)/8, $0x40fb392e21698552 +GLOBL ·logxm<> + 0(SB), RODATA, $128 + +// Log returns the natural logarithm of the argument. +// +// Special cases are: +// Log(+Inf) = +Inf +// Log(0) = -Inf +// Log(x < 0) = NaN +// Log(NaN) = NaN +// The algorithm used is minimax polynomial approximation using a table of +// polynomial coefficients determined with a Remez exchange algorithm. + +TEXT ·logAsm(SB), NOSPLIT, $0-16 + FMOVD x+0(FP), F0 + MOVD $·logrodataL21<>+0(SB), R9 + MOVH $0x8006, R4 + LGDR F0, R1 + MOVD $0x3FF0000000000000, R6 + SRAD $48, R1, R1 + MOVD $0x40F03E8000000000, R8 + SUBW R1, R4 + RISBGZ $32, $59, $0, R4, R2 + RISBGN $0, $15, $48, R2, R6 + RISBGN $16, $31, $32, R2, R8 + MOVW R1, R7 + CMPBGT R7, $22, L17 + LTDBR F0, F0 + MOVD $·logx43f<>+0(SB), R1 + FMOVD 0(R1), F2 + BLEU L3 + MOVH $0x8005, R12 + MOVH $0x8405, R0 + BR L15 +L7: + LTDBR F0, F0 + BLEU L3 +L15: + FMUL F2, F0 + LGDR F0, R1 + SRAD $48, R1, R1 + SUBW R1, R0, R2 + SUBW R1, R12, R3 + BYTE $0x18 //lr %r4,%r2 + BYTE $0x42 + ANDW $0xFFFFFFF0, R3 + ANDW $0xFFFFFFF0, R2 + BYTE $0x18 //lr %r5,%r1 + BYTE $0x51 + MOVW R1, R7 + CMPBLE R7, $22, L7 + RISBGN $0, $15, $48, R3, R6 + RISBGN $16, $31, $32, R2, R8 +L2: + MOVH R5, R5 + MOVH $0x7FEF, R1 + CMPW R5, R1 + BGT L1 + LDGR R6, F2 + FMUL F2, F0 + RISBGZ $57, $59, $3, R4, R4 + FMOVD 80(R9), F2 + MOVD $·logxm<>+0(SB), R7 + ADD R7, R4 + FMOVD 72(R9), F4 + WORD $0xED004000 //madb %f2,%f0,0(%r4) + BYTE $0x20 + BYTE $0x1E + FMOVD 64(R9), F1 + FMOVD F2, F0 + FMOVD 56(R9), F2 + WFMADB V0, V2, V4, V2 + WFMDB V0, V0, V6 + FMOVD 48(R9), F4 + WFMADB V0, V2, V4, V2 + FMOVD 40(R9), F4 + WFMADB V2, V6, V1, V2 + FMOVD 32(R9), F1 + WFMADB V6, V4, V1, V4 + FMOVD 24(R9), F1 + WFMADB V6, V2, V1, V2 + FMOVD 16(R9), F1 + WFMADB V6, V4, V1, V4 + MOVD $·logxl1<>+0(SB), R1 + FMOVD 8(R9), F1 + WFMADB V6, V2, V1, V2 + FMOVD 0(R9), F1 + WFMADB V6, V4, V1, V4 + FMOVD 8(R4), F1 + WFMADB V0, V2, V4, V2 + LDGR R8, F4 + WFMADB V6, V2, V0, V2 + WORD $0xED401000 //msdb %f1,%f4,0(%r1) + BYTE $0x10 + BYTE $0x1F + MOVD ·logxl2<>+0(SB), R1 + WORD $0xB3130001 //lcdbr %f0,%f1 + LDGR R1, F4 + WFMADB V0, V4, V2, V0 +L1: + FMOVD F0, ret+8(FP) + RET +L3: + LTDBR F0, F0 + BEQ L20 + BGE L1 + BVS L1 + + MOVD $·logxnan<>+0(SB), R1 + FMOVD 0(R1), F0 + BR L1 +L20: + MOVD $·logxminf<>+0(SB), R1 + FMOVD 0(R1), F0 + FMOVD F0, ret+8(FP) + RET +L17: + BYTE $0x18 //lr %r5,%r1 + BYTE $0x51 + BR L2 |