Handle more pow cases (#61)

README.md

@@ -25,7 +25,7 @@ five files to get started:
 wget https://justine.lol/cosmopolitan/cosmopolitan.zip
 unzip cosmopolitan.zip
 printf 'main() { printf("hello world\\n"); }\n' >hello.c
-gcc -g -Og -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
+gcc -g -Os -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
   -fno-omit-frame-pointer -pg -mnop-mcount \
   -o hello.com.dbg hello.c -fuse-ld=bfd -Wl,-T,ape.lds \
   -include cosmopolitan.h crt.o ape.o cosmopolitan.a
@@ -58,7 +58,7 @@ find o -name \*.com | xargs ls -rShal | less
 | Intel           | Core        | 2006  |
 | New Technology  | Vista       | 2006  |
 | GNU/Systemd     | 2.6.18      | 2007  |
-| XNU's Not UNIX | 15.6        | 2018  |
+| XNU's Not UNIX! | 15.6        | 2018  |
 | FreeBSD         | 12          | 2018  |
 | OpenBSD         | 6.4         | 2018  |
 | NetBSD          | 9.1         | 2020  |

libc/tinymath/powl.c

@@ -31,7 +31,11 @@ long double powl(long double x, long double y) {
           asm("fprem" : "=t"(t) : "0"(u), "u"(1.L));
           asm("f2xm1" : "=t"(t) : "0"(t));
           asm("fscale" : "=t"(t) : "0"(t + 1), "u"(u));
-          return copysignl(t, x);
+          if (signbit(x)) {
+            if (y != truncl(y)) return -NAN;
+            if (!signbit(y) || ((int64_t)y & 1)) t = -t;
+          }
+          return t;
         } else if (y > 0) {
           return 0;
         } else if (!y) {

test/libc/fmt/palandprintf_test.c

@@ -406,6 +406,7 @@ TEST(sprintf, test_float) {
 #ifndef __FINITE_MATH_ONLY__
   EXPECT_STREQ("nan", Format("%.4f", NAN));
 #endif
+  EXPECT_STREQ("-0.0000", Format("%.4f", -0.));
   EXPECT_STREQ("3.1415", Format("%.4f", 3.1415354));
   EXPECT_STREQ("30343.142", Format("%.3f", 30343.1415354));
   EXPECT_STREQ("34", Format("%.0f", 34.1415354));

test/libc/tinymath/powl_test.c

@@ -39,7 +39,6 @@ void SetUp(void) {
 TEST(powl, test) {
   EXPECT_STREQ("27", gc(xdtoal(powl(3, 3))));
   EXPECT_STREQ("-27", gc(xdtoal(powl(-3, 3))));
-  EXPECT_STREQ("-1", gc(xdtoal(powl(-1, 1.1))));
   EXPECT_STREQ("1e+4932", gc(xdtoal(powl(10, 4932))));
   EXPECT_STREQ("INFINITY", gc(xdtoal(powl(10, 4933))));
   EXPECT_STREQ("0", gc(xdtoal(powl(10, -5000))));
@@ -83,12 +82,15 @@ TEST(powl, test) {
   EXPECT_STREQ("-INFINITY", gc(xdtoal(powl(-0., -(MAX(rando, 1) | 1)))));
   EXPECT_STREQ("INFINITY", gc(xdtoal(powl(0, -(rando & -2)))));
   EXPECT_STREQ("INFINITY", gc(xdtoal(powl(-0., -(rando & -2)))));
+  EXPECT_TRUE(isnan(powl(-3, 1. / MAX(rando, 2))));
+  EXPECT_TRUE(isnan(powl(-3, -(1. / MAX(rando, 2)))));
+  EXPECT_STREQ("-.3333333333333333", gc(xdtoal(powl(-3, -1))));
+  EXPECT_STREQ(".1111111111111111", gc(xdtoal(powl(-3, -2))));
 }
 
 TEST(pow, test) {
   EXPECT_STREQ("27", gc(xdtoa(pow(3, 3))));
   EXPECT_STREQ("-27", gc(xdtoa(pow(-3, 3))));
-  EXPECT_STREQ("-1", gc(xdtoa(pow(-1, 1.1))));
   EXPECT_STREQ("1e+308", gc(xdtoa(pow(10, 308))));
   EXPECT_STREQ("INFINITY", gc(xdtoa(pow(10, 309))));
   EXPECT_STREQ("0", gc(xdtoa(pow(10, -5000))));
@@ -132,12 +134,13 @@ TEST(pow, test) {
   EXPECT_STREQ("-INFINITY", gc(xdtoa(pow(-0., -(MAX(rando, 1) | 1)))));
   EXPECT_STREQ("INFINITY", gc(xdtoa(pow(0, -(rando & -2)))));
   EXPECT_STREQ("INFINITY", gc(xdtoa(pow(-0., -(rando & -2)))));
+  EXPECT_STREQ("-.333333333333333", gc(xdtoa(pow(-3, -1))));
+  EXPECT_STREQ(".111111111111111", gc(xdtoa(pow(-3, -2))));
 }
 
 TEST(powf, test) {
   EXPECT_STREQ("27", gc(xdtoaf(powf(3, 3))));
   EXPECT_STREQ("-27", gc(xdtoaf(powf(-3, 3))));
-  EXPECT_STREQ("-1", gc(xdtoaf(powf(-1, 1.1))));
   EXPECT_STREQ("1e+38", gc(xdtoaf(powf(10, 38))));
   EXPECT_STREQ("INFINITY", gc(xdtoaf(powf(10, 39))));
   EXPECT_STREQ("0", gc(xdtoaf(powf(10, -5000))));
@@ -181,6 +184,8 @@ TEST(powf, test) {
   EXPECT_STREQ("-INFINITY", gc(xdtoaf(powf(-0., -(MAX(rando, 1) | 1)))));
   EXPECT_STREQ("INFINITY", gc(xdtoaf(powf(0, -(rando & -2)))));
   EXPECT_STREQ("INFINITY", gc(xdtoaf(powf(-0., -(rando & -2)))));
+  EXPECT_STREQ("-.333333", gc(xdtoaf(powf(-3, -1))));
+  EXPECT_STREQ(".111111", gc(xdtoaf(powf(-3, -2))));
 }
 
 BENCH(powl, bench) {

tool/build/calculator.ctest

@@ -7,7 +7,7 @@
 81 3 // 27 = assert
 2 8 ** 256 = assert
 17 10 % 7 = assert
-17 10 mod 7 = assert
+17 10 fmod 7 = assert
 
 # FLOATING POINT
 .1 .2 + .3 - abs epsilon < assert

tool/build/calculator.inc

@@ -29,11 +29,13 @@ M(1, i, "ungray", Ungray, ungray(x), "inverse gray coding")
 M(1, i, "popcnt", Popcnt, Popcnt(x), "count bits")
 
 M(1, g, "abs", Abs, fabsl(x), "absolute value")
-M(2, g, "min", Min, MIN(x, y), "pops two values and pushes minimum")
+M(2, g, "min", Min, fminl(x, y), "pops two values and pushes minimum")
-M(2, g, "max", Max, MAX(x, y), "pops two values and pushes maximum")
+M(2, g, "max", Max, fmaxl(x, y), "pops two values and pushes maximum")
 
-M(2, g, "mod", Euclidean, emodl(x, y), "euclidean remainder")
+M(2, g, "fmod", Fmod, fmodl(x, y), "trunc remainder")
-M(2, g, "rem", Remainder, remainderl(x, y), "float remainder")
+M(2, g, "emod", Emod, emodl(x, y), "euclidean remainder")
+M(2, g, "remainder", Remainder, remainderl(x, y), "rint remainder")
+M(2, g, "hypot", Hypot, hypotl(x, y), "euclidean distance")
 
 M(0, i, "false", False, 0, "0")
 M(0, i, "true", True, 1, "1")
@@ -49,16 +51,21 @@ M(0, f, "l2t", Fldl2t, M_LOG2_10, "log₂10")
 M(0, f, "lg2", Fldlg2, M_LOG10_2, "log₁₀2")
 M(0, f, "ln2", Fldln2, M_LN2, "logₑ2")
 M(0, f, "l2e", Fldl2e, M_LOG2E, "logₑ10")
+M(2, f, "nextafter", Nextafter, nextafterl(x, y), "next ulp")
+M(1, f, "significand", Significand, significandl(x), "mantissa")
 
 M(1, f, "sqrt", Sqrt, sqrtl(x), "√𝑥")
 M(1, f, "exp", Exp, expl(x), "𝑒ˣ")
+M(1, g, "expm1", Expm1, expm1l(x), "𝑒ˣ-1")
 M(1, g, "exp2", Exp2, exp2l(x), "2ˣ")
 M(1, g, "exp10", Exp10, exp10l(x), "10ˣ")
 M(2, g, "ldexp", Ldexp, ldexpl(x, y), "𝑥×2ʸ")
+M(2, g, "scalb", Scalb, scalbl(x, y), "𝑥×2ʸ")
 
 M(1, f, "log", Log, logl(x), "logₑ𝑥")
 M(1, g, "log2", Log2, log2l(x), "log₂𝑥")
 M(1, g, "log10", Log10, log10l(x), "log₁₀𝑥")
+M(1, g, "ilogb", Ilogb, ilogbl(x), "exponent")
 
 M(1, g, "sin", Sin, sinl(x), "sine")
 M(1, g, "cos", Cos, cosl(x), "cosine")
@@ -68,10 +75,17 @@ M(1, g, "acos", Acos, acosl(x), "arccosine")
 M(1, g, "atan", Atan, atanl(x), "arctangent")
 M(2, g, "atan2", Atan2, atan2l(x, y), "arctangent of 𝑥/𝑦")
 
+M(1, g, "sinh", Sinh, sinhl(x), "hyperbolic sine")
+M(1, g, "cosh", Cosh, coshl(x), "hyperbolic cosine")
+M(1, g, "tanh", Tanh, tanhl(x), "hyperbolic tangent")
+M(1, g, "asinh", Asinh, asinhl(x), "hyperbolic arcsine")
+M(1, g, "acosh", Acosh, acoshl(x), "hyperbolic arccosine")
+M(1, g, "atanh", Atanh, atanhl(x), "hyperbolic arctangent")
+
 M(1, g, "round", Round, roundl(x), "round away from zero")
 M(1, g, "trunc", Trunc, truncl(x), "round towards zero")
 M(1, g, "rint", Rint, rintl(x), "round to even")
-M(1, g, "nearbyint", Nearbyint, nearbyint(x), "round to nearest integer")
+M(1, g, "nearbyint", Nearbyint, nearbyintl(x), "round to nearest integer")
 M(1, g, "ceil", Ceil, ceill(x), "smallest integral not less than 𝑥")
 M(1, g, "floor", Floor, floorl(x), "largest integral not greater than 𝑥")