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libzigc: hypot (#31104)
First time contribution. Implements hypot for libzigc #30978. Commands i run: ``` $ stage3/bin/zig build -p stage4 -Denable-llvm -Dno-lib $ stage4/bin/zig build test-libc -Dlibc-test-path=../../libc-test -Dtest-filter=hypot --summary line -fqemu -fwasmtime Build Summary: 725/737 steps succeeded (12 skipped) ``` I also changed std.math.hypot becuase some libc-tests raised fp exceptions. Example: ``` ../../libc-test/src/math/special/hypot.h:8: bad fp exception: RN hypot(0x1p-1074,0x0p+0)=0x1p-1074, want 0 got INEXACT|UNDERFLOW ../../libc-test/src/math/special/hypot.h:9: bad fp exception: RN hypot(0x1p-1074,-0x0p+0)=0x1p-1074, want 0 got INEXACT|UNDERFLOW ``` I also run this command as a quick sanity check: ``` $ stage4/bin/zig build test-std -Dtest-filter=hypot -Dtest-target-filter=x86_64-linux-musl --summary line Build Summary: 5/5 steps succeeded; 136/136 tests passed ``` Reviewed-on: https://codeberg.org/ziglang/zig/pulls/31104 Reviewed-by: Andrew Kelley <andrew@ziglang.org> Co-authored-by: Pivok <pivoc@protonmail.com> Co-committed-by: Pivok <pivoc@protonmail.com>
This commit is contained in:
Pivok
@@ -41,6 +41,7 @@ comptime {
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@export(&atanl, .{ .name = "atanl", .linkage = common.linkage, .visibility = common.visibility });
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@export(&cbrt, .{ .name = "cbrt", .linkage = common.linkage, .visibility = common.visibility });
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@export(&cbrtf, .{ .name = "cbrtf", .linkage = common.linkage, .visibility = common.visibility });
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@export(&hypot, .{ .name = "hypot", .linkage = common.linkage, .visibility = common.visibility });
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@export(&pow, .{ .name = "pow", .linkage = common.linkage, .visibility = common.visibility });
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}
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@@ -118,6 +119,10 @@ fn cbrtf(x: f32) callconv(.c) f32 {
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return math.cbrt(x);
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}
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fn hypot(x: f64, y: f64) callconv(.c) f64 {
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return math.hypot(x, y);
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}
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fn pow(x: f64, y: f64) callconv(.c) f64 {
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return math.pow(f64, x, y);
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}
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Vendored
-67
@@ -1,67 +0,0 @@
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#include <math.h>
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#include <stdint.h>
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#include <float.h>
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#if FLT_EVAL_METHOD > 1U && LDBL_MANT_DIG == 64
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#define SPLIT (0x1p32 + 1)
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#else
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#define SPLIT (0x1p27 + 1)
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#endif
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static void sq(double_t *hi, double_t *lo, double x)
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{
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double_t xh, xl, xc;
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xc = (double_t)x*SPLIT;
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xh = x - xc + xc;
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xl = x - xh;
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*hi = (double_t)x*x;
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*lo = xh*xh - *hi + 2*xh*xl + xl*xl;
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}
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double hypot(double x, double y)
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{
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union {double f; uint64_t i;} ux = {x}, uy = {y}, ut;
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int ex, ey;
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double_t hx, lx, hy, ly, z;
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/* arrange |x| >= |y| */
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ux.i &= -1ULL>>1;
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uy.i &= -1ULL>>1;
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if (ux.i < uy.i) {
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ut = ux;
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ux = uy;
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uy = ut;
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}
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/* special cases */
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ex = ux.i>>52;
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ey = uy.i>>52;
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x = ux.f;
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y = uy.f;
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/* note: hypot(inf,nan) == inf */
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if (ey == 0x7ff)
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return y;
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if (ex == 0x7ff || uy.i == 0)
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return x;
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/* note: hypot(x,y) ~= x + y*y/x/2 with inexact for small y/x */
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/* 64 difference is enough for ld80 double_t */
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if (ex - ey > 64)
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return x + y;
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/* precise sqrt argument in nearest rounding mode without overflow */
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/* xh*xh must not overflow and xl*xl must not underflow in sq */
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z = 1;
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if (ex > 0x3ff+510) {
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z = 0x1p700;
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x *= 0x1p-700;
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y *= 0x1p-700;
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} else if (ey < 0x3ff-450) {
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z = 0x1p-700;
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x *= 0x1p700;
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y *= 0x1p700;
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}
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sq(&hx, &lx, x);
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sq(&hy, &ly, y);
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return z*sqrt(ly+lx+hy+hx);
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}
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Vendored
-45
@@ -1,45 +0,0 @@
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.global hypot
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.type hypot,@function
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hypot:
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mov 8(%esp),%eax
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mov 16(%esp),%ecx
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add %eax,%eax
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add %ecx,%ecx
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and %eax,%ecx
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cmp $0xffe00000,%ecx
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jae 2f
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or 4(%esp),%eax
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jnz 1f
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fldl 12(%esp)
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fabs
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ret
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1: mov 16(%esp),%eax
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add %eax,%eax
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or 12(%esp),%eax
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jnz 1f
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fldl 4(%esp)
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fabs
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ret
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1: fldl 4(%esp)
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fld %st(0)
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fmulp
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fldl 12(%esp)
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fld %st(0)
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fmulp
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faddp
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fsqrt
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ret
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2: sub $0xffe00000,%eax
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or 4(%esp),%eax
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jnz 1f
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fldl 4(%esp)
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fabs
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ret
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1: mov 16(%esp),%eax
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add %eax,%eax
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sub $0xffe00000,%eax
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or 12(%esp),%eax
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fldl 12(%esp)
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jnz 1f
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fabs
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1: ret
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@@ -6,10 +6,10 @@ const isNan = math.isNan;
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const isInf = math.isInf;
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const inf = math.inf;
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const nan = math.nan;
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const floatEpsAt = math.floatEpsAt;
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const floatEps = math.floatEps;
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const floatMin = math.floatMin;
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const floatMax = math.floatMax;
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const floatTrueMin = math.floatTrueMin;
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/// Returns sqrt(x * x + y * y), avoiding unnecessary overflow and underflow.
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///
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@@ -30,8 +30,7 @@ pub fn hypot(x: anytype, y: anytype) @TypeOf(x, y) {
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}
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const lower = @sqrt(floatMin(T));
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const upper = @sqrt(floatMax(T) / 2);
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const incre = @sqrt(floatEps(T) / 2);
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const scale = floatEpsAt(T, incre);
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const scale = floatTrueMin(T) * upper;
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const hypfn = if (emulateFma(T)) hypotUnfused else hypotFused;
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var major: T = x;
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var minor: T = y;
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@@ -46,7 +45,8 @@ pub fn hypot(x: anytype, y: anytype) @TypeOf(x, y) {
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major = minor;
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minor = tempo;
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}
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if (major * incre >= minor) return major;
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if (minor == 0.0) return major;
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if (major - minor == major) return major;
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if (major > upper) return hypfn(T, major * scale, minor * scale) / scale;
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if (minor < lower) return hypfn(T, major / scale, minor / scale) * scale;
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return hypfn(T, major, minor);
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@@ -874,7 +874,6 @@ const src_files = [_][]const u8{
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"musl/src/math/frexp.c",
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"musl/src/math/frexpf.c",
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"musl/src/math/frexpl.c",
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"musl/src/math/hypot.c",
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"musl/src/math/hypotf.c",
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"musl/src/math/hypotl.c",
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"musl/src/math/i386/acosf.s",
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@@ -890,7 +889,6 @@ const src_files = [_][]const u8{
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"musl/src/math/i386/expl.s",
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"musl/src/math/i386/expm1l.s",
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"musl/src/math/i386/hypotf.s",
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"musl/src/math/i386/hypot.s",
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"musl/src/math/i386/__invtrigl.s",
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"musl/src/math/i386/ldexpf.s",
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"musl/src/math/i386/ldexpl.s",
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@@ -730,7 +730,6 @@ const libc_top_half_src_files = [_][]const u8{
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"musl/src/math/frexp.c",
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"musl/src/math/frexpf.c",
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"musl/src/math/frexpl.c",
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"musl/src/math/hypot.c",
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"musl/src/math/hypotf.c",
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"musl/src/math/hypotl.c",
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"musl/src/math/ilogb.c",
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