diff options
Diffstat (limited to 'system/musl/complex-math.patch')
| -rw-r--r-- | system/musl/complex-math.patch | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/system/musl/complex-math.patch b/system/musl/complex-math.patch new file mode 100644 index 000000000..fff4b59c1 --- /dev/null +++ b/system/musl/complex-math.patch @@ -0,0 +1,59 @@ +From ae2a01da2e388535da243b3d974aef74a3c06ae0 Mon Sep 17 00:00:00 2001 +From: Rich Felker <dalias@aerifal.cx> +Date: Mon, 9 Apr 2018 12:33:17 -0400 +Subject: fix wrong result in casin and many related complex functions + +the factor of -i noted in the comment at the top of casin.c was +omitted from the actual code, yielding a result rotated 90 degrees and +propagating into errors in other functions defined in terms of casin. + +implement multiplication by -i as a rotation of the real and imaginary +parts of the result, rather than by actual multiplication, since the +latter cannot be optimized without knowledge that the operand is +finite. here, the rotation is the actual intent, anyway. +--- + src/complex/casin.c | 3 ++- + src/complex/casinf.c | 3 ++- + src/complex/casinl.c | 3 ++- + 3 files changed, 6 insertions(+), 3 deletions(-) + +diff --git a/src/complex/casin.c b/src/complex/casin.c +index dfdda98..01ed618 100644 +--- a/src/complex/casin.c ++++ b/src/complex/casin.c +@@ -12,5 +12,6 @@ double complex casin(double complex z) + x = creal(z); + y = cimag(z); + w = CMPLX(1.0 - (x - y)*(x + y), -2.0*x*y); +- return clog(CMPLX(-y, x) + csqrt(w)); ++ double complex r = clog(CMPLX(-y, x) + csqrt(w)); ++ return CMPLX(cimag(r), -creal(r)); + } +diff --git a/src/complex/casinf.c b/src/complex/casinf.c +index 93f0e33..4fcb76f 100644 +--- a/src/complex/casinf.c ++++ b/src/complex/casinf.c +@@ -10,5 +10,6 @@ float complex casinf(float complex z) + x = crealf(z); + y = cimagf(z); + w = CMPLXF(1.0 - (x - y)*(x + y), -2.0*x*y); +- return clogf(CMPLXF(-y, x) + csqrtf(w)); ++ float complex r = clogf(CMPLXF(-y, x) + csqrtf(w)); ++ return CMPLXF(cimagf(r), -crealf(r)); + } +diff --git a/src/complex/casinl.c b/src/complex/casinl.c +index 0916c60..3b7ceba 100644 +--- a/src/complex/casinl.c ++++ b/src/complex/casinl.c +@@ -15,6 +15,7 @@ long double complex casinl(long double complex z) + x = creall(z); + y = cimagl(z); + w = CMPLXL(1.0 - (x - y)*(x + y), -2.0*x*y); +- return clogl(CMPLXL(-y, x) + csqrtl(w)); ++ long double complex r = clogl(CMPLXL(-y, x) + csqrtl(w)); ++ return CMPLXL(cimagl(r), -creall(r)); + } + #endif +-- +cgit v0.11.2 + |