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 // 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. package runtime #include "runtime.h" func complex128div(n Complex128, d Complex128) (q Complex128) { int32 ninf, dinf, nnan, dnan; float64 a, b, ratio, denom; // Special cases as in C99. ninf = n.real == runtime·posinf || n.real == runtime·neginf || n.imag == runtime·posinf || n.imag == runtime·neginf; dinf = d.real == runtime·posinf || d.real == runtime·neginf || d.imag == runtime·posinf || d.imag == runtime·neginf; nnan = !ninf && (ISNAN(n.real) || ISNAN(n.imag)); dnan = !dinf && (ISNAN(d.real) || ISNAN(d.imag)); if(nnan || dnan) { q.real = runtime·nan; q.imag = runtime·nan; } else if(ninf && !dinf) { q.real = runtime·posinf; q.imag = runtime·posinf; } else if(!ninf && dinf) { q.real = 0; q.imag = 0; } else if(d.real == 0 && d.imag == 0) { if(n.real == 0 && n.imag == 0) { q.real = runtime·nan; q.imag = runtime·nan; } else { q.real = runtime·posinf; q.imag = runtime·posinf; } } else { // Standard complex arithmetic, factored to avoid unnecessary overflow. a = d.real; if(a < 0) a = -a; b = d.imag; if(b < 0) b = -b; if(a <= b) { ratio = d.real/d.imag; denom = d.real*ratio + d.imag; q.real = (n.real*ratio + n.imag) / denom; q.imag = (n.imag*ratio - n.real) / denom; } else { ratio = d.imag/d.real; denom = d.imag*ratio + d.real; q.real = (n.imag*ratio + n.real) / denom; q.imag = (n.imag - n.real*ratio) / denom; } } }