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Diffstat (limited to 'src/pkg/math/hypot_386.s')
| -rw-r--r-- | src/pkg/math/hypot_386.s | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/pkg/math/hypot_386.s b/src/pkg/math/hypot_386.s new file mode 100644 index 000000000..70ff19a17 --- /dev/null +++ b/src/pkg/math/hypot_386.s @@ -0,0 +1,57 @@ +// Copyright 2010 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. + +// func Hypot(x, y float64) float64 +TEXT ·Hypot(SB),7,$0 +// test bits for not-finite + MOVL xh+4(FP), AX // high word x + ANDL $0x7ff00000, AX + CMPL AX, $0x7ff00000 + JEQ not_finite + MOVL yh+12(FP), AX // high word y + ANDL $0x7ff00000, AX + CMPL AX, $0x7ff00000 + JEQ not_finite + FMOVD x+0(FP), F0 // F0=x + FABS // F0=|x| + FMOVD y+8(FP), F0 // F0=y, F1=|x| + FABS // F0=|y|, F1=|x| + FUCOMI F0, F1 // compare F0 to F1 + JCC 2(PC) // jump if F0 >= F1 + FXCHD F0, F1 // F0=|x| (larger), F1=|y| (smaller) + FTST // compare F0 to 0 + FSTSW AX + ANDW $0x4000, AX + JNE 10(PC) // jump if F0 = 0 + FXCHD F0, F1 // F0=y (smaller), F1=x (larger) + FDIVD F1, F0 // F0=y(=y/x), F1=x + FMULD F0, F0 // F0=y*y, F1=x + FLD1 // F0=1, F1=y*y, F2=x + FADDDP F0, F1 // F0=1+y*y, F1=x + FSQRT // F0=sqrt(1+y*y), F1=x + FMULDP F0, F1 // F0=x*sqrt(1+y*y) + FMOVDP F0, r+16(FP) + RET + FMOVDP F0, F1 // F0=0 + FMOVDP F0, r+16(FP) + RET +not_finite: +// test bits for -Inf or +Inf + MOVL xh+4(FP), AX // high word x + ORL xl+0(FP), AX // low word x + ANDL $0x7fffffff, AX + CMPL AX, $0x7ff00000 + JEQ is_inf + MOVL yh+12(FP), AX // high word y + ORL yl+8(FP), AX // low word y + ANDL $0x7fffffff, AX + CMPL AX, $0x7ff00000 + JEQ is_inf + MOVL $0x7ff00000, rh+20(FP) // return NaN = 0x7FF0000000000001 + MOVL $0x00000001, rl+16(FP) + RET +is_inf: + MOVL AX, rh+20(FP) // return +Inf = 0x7FF0000000000000 + MOVL $0x00000000, rl+16(FP) + RET |