| author |  Andrew Kelley <andrew@ziglang.org> 2017-10-24 21:44:49-04:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2017-10-24 21:44:49-04:00 |
| log | 1e784839f1b6ac116f7cae35fa4a8069902283b6 |
| tree | c54d2cd1e058c85aaf3d2abe21ca710256ef0507 |
| parent | 1828f8eb8e1514578ed2da8d58536903f94b7ed0 |
| parent | 262b7428cfad88de9d328773cc4bae6151b8a030 |
Merge branch 'float-printing' of https://github.com/scurest/zig into better-float-printing
2 files changed, 37 insertions(+), 24 deletions(-)
std/fmt/errol/index.zig+9-13
| ... | ... | @@ -32,13 +32,13 @@ pub fn errol3(value: f64, buffer: []u8) -> FloatDecimal { |
| 32 | 32 | fn errol3u(val: f64, buffer: []u8) -> FloatDecimal { |
| 33 | 33 | // check if in integer or fixed range |
| 34 | 34 | |
| 35 | if (val >= 9.007199254740992e15 and val < 3.40282366920938e+38) { | |
| 35 | if (val > 9.007199254740992e15 and val < 3.40282366920938e+38) { | |
| 36 | 36 | return errolInt(val, buffer); |
| 37 | 37 | } else if (val >= 16.0 and val < 9.007199254740992e15) { |
| 38 | 38 | return errolFixed(val, buffer); |
| 39 | 39 | } |
| 40 | 40 | |
| 41 | ||
| 41 | ||
| 42 | 42 | // normalize the midpoint |
| 43 | 43 | |
| 44 | 44 | const e = math.frexp(val).exponent; |
| ... | ... | @@ -138,7 +138,7 @@ fn tableLowerBound(k: u64) -> usize { |
| 138 | 138 | |
| 139 | 139 | while (j < enum3.len) { |
| 140 | 140 | if (enum3[j] < k) { |
| 141 | j = 2 * k + 2; | |
| 141 | j = 2 * j + 2; | |
| 142 | 142 | } else { |
| 143 | 143 | i = j; |
| 144 | 144 | j = 2 * j + 1; |
| ... | ... | @@ -217,7 +217,7 @@ fn hpMul10(hp: &HP) { |
| 217 | 217 | |
| 218 | 218 | hp.val *= 10.0; |
| 219 | 219 | hp.off *= 10.0; |
| 220 | ||
| 220 | ||
| 221 | 221 | var off = hp.val; |
| 222 | 222 | off -= val * 8.0; |
| 223 | 223 | off -= val * 2.0; |
| ... | ... | @@ -235,13 +235,13 @@ fn hpMul10(hp: &HP) { |
| 235 | 235 | fn errolInt(val: f64, buffer: []u8) -> FloatDecimal { |
| 236 | 236 | const pow19 = u128(1e19); |
| 237 | 237 | |
| 238 | assert((val >= 9.007199254740992e15) and val < (3.40282366920938e38)); | |
| 238 | assert((val > 9.007199254740992e15) and val < (3.40282366920938e38)); | |
| 239 | 239 | |
| 240 | 240 | var mid = u128(val); |
| 241 | 241 | var low: u128 = mid - fpeint((fpnext(val) - val) / 2.0); |
| 242 | 242 | var high: u128 = mid + fpeint((val - fpprev(val)) / 2.0); |
| 243 | 243 | |
| 244 | if (@bitCast(u64, val) & 0x1 != 0) { | |
| 244 | if (@bitCast(u64, val) & 0x1 != 0) { | |
| 245 | 245 | high -= 1; |
| 246 | 246 | } else { |
| 247 | 247 | low -= 1; |
| ... | ... | @@ -347,11 +347,11 @@ fn errolFixed(val: f64, buffer: []u8) -> FloatDecimal { |
| 347 | 347 | } |
| 348 | 348 | |
| 349 | 349 | fn fpnext(val: f64) -> f64 { |
| 350 | return @bitCast(f64, @bitCast(u64, val) + 1); | |
| 350 | return @bitCast(f64, @bitCast(u64, val) +% 1); | |
| 351 | 351 | } |
| 352 | 352 | |
| 353 | 353 | fn fpprev(val: f64) -> f64 { |
| 354 | return @bitCast(f64, @bitCast(u64, val) - 1); | |
| 354 | return @bitCast(f64, @bitCast(u64, val) -% 1); | |
| 355 | 355 | } |
| 356 | 356 | |
| 357 | 357 | pub const c_digits_lut = []u8 { |
| ... | ... | @@ -510,10 +510,6 @@ fn u64toa(value_param: u64, buffer: []u8) -> usize { |
| 510 | 510 | buf_index += 1; |
| 511 | 511 | buffer[buf_index] = c_digits_lut[d8]; |
| 512 | 512 | buf_index += 1; |
| 513 | buffer[buf_index] = c_digits_lut[d8]; | |
| 514 | buf_index += 1; | |
| 515 | buffer[buf_index] = c_digits_lut[d8]; | |
| 516 | buf_index += 1; | |
| 517 | 513 | buffer[buf_index] = c_digits_lut[d8 + 1]; |
| 518 | 514 | buf_index += 1; |
| 519 | 515 | } else { |
| ... | ... | @@ -613,7 +609,7 @@ fn fpeint(from: f64) -> u128 { |
| 613 | 609 | const bits = @bitCast(u64, from); |
| 614 | 610 | assert((bits & ((1 << 52) - 1)) == 0); |
| 615 | 611 | |
| 616 | return u64(1) << u6(((bits >> 52) - 1023)); | |
| 612 | return u128(1) << @truncate(u7, (bits >> 52) -% 1023); | |
| 617 | 613 | } |
| 618 | 614 | |
| 619 | 615 |
std/fmt/index.zig+28-11
| ... | ... | @@ -244,30 +244,47 @@ pub fn formatBuf(buf: []const u8, width: usize, |
| 244 | 244 | } |
| 245 | 245 | |
| 246 | 246 | pub fn formatFloat(value: var, context: var, output: fn(@typeOf(context), []const u8)->bool) -> bool { |
| 247 | var buffer: [20]u8 = undefined; | |
| 248 | const float_decimal = errol3(f64(value), buffer[0..]); | |
| 249 | if (float_decimal.exp != 0) { | |
| 250 | if (!output(context, float_decimal.digits[0..1])) | |
| 251 | return false; | |
| 252 | } else { | |
| 253 | if (!output(context, "0")) | |
| 247 | var x = f64(value); | |
| 248 | ||
| 249 | // Errol doesn't handle these special cases. | |
| 250 | if (math.isNan(x)) { | |
| 251 | return output(context, "NaN"); | |
| 252 | } | |
| 253 | if (math.signbit(x)) { | |
| 254 | if (!output(context, "-")) | |
| 254 | 255 | return false; |
| 256 | x = -x; | |
| 255 | 257 | } |
| 258 | if (math.isPositiveInf(x)) { | |
| 259 | return output(context, "Infinity"); | |
| 260 | } | |
| 261 | if (x == 0.0) { | |
| 262 | return output(context, "0.0"); | |
| 263 | } | |
| 264 | ||
| 265 | var buffer: [32]u8 = undefined; | |
| 266 | const float_decimal = errol3(x, buffer[0..]); | |
| 267 | if (!output(context, float_decimal.digits[0..1])) | |
| 268 | return false; | |
| 256 | 269 | if (!output(context, ".")) |
| 257 | 270 | return false; |
| 258 | 271 | if (float_decimal.digits.len > 1) { |
| 259 | const start = if (float_decimal.exp == 0) usize(0) else usize(1); | |
| 260 | if (!output(context, float_decimal.digits[start .. math.min(usize(7), float_decimal.digits.len)])) | |
| 272 | const num_digits = if (@typeOf(value) == f32) { | |
| 273 | math.min(usize(9), float_decimal.digits.len) | |
| 274 | } else { | |
| 275 | float_decimal.digits.len | |
| 276 | }; | |
| 277 | if (!output(context, float_decimal.digits[1 .. num_digits])) | |
| 261 | 278 | return false; |
| 262 | 279 | } else { |
| 263 | 280 | if (!output(context, "0")) |
| 264 | 281 | return false; |
| 265 | 282 | } |
| 266 | 283 | |
| 267 | if (float_decimal.exp != 1 and float_decimal.exp != 0) { | |
| 284 | if (float_decimal.exp != 1) { | |
| 268 | 285 | if (!output(context, "e")) |
| 269 | 286 | return false; |
| 270 | if (!formatInt(float_decimal.exp, 10, false, 0, context, output)) | |
| 287 | if (!formatInt(float_decimal.exp - 1, 10, false, 0, context, output)) | |
| 271 | 288 | return false; |
| 272 | 289 | } |
| 273 | 290 | return true; |