From f9c6903d4a90b59c328f4fa05d2be9e0ce1c5189 Mon Sep 17 00:00:00 2001 From: Jeremy Huddleston Date: Wed, 5 Oct 2011 15:02:52 -0700 Subject: dix: add utility functions for double to/fro FP1616/FP3232 conversion Co-authored-by: Jeremy Huddleston Signed-off-by: Peter Hutterer Reviewed-by: Peter Hutterer Reviewed-by: Jeremy Huddleston Reviewed-by: Mark Kettenis --- dix/inpututils.c | 63 +++++++++++++++++++++++++ include/inpututils.h | 6 +++ test/input.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+) diff --git a/dix/inpututils.c b/dix/inpututils.c index 0a3d3d8b4..cd4577347 100644 --- a/dix/inpututils.c +++ b/dix/inpututils.c @@ -759,3 +759,66 @@ input_option_set_value(InputOption *opt, const char *value) if (value) opt->value = strdup(value); } + + +/* FP1616/FP3232 conversion functions. + * Fixed point types are encoded as signed integral and unsigned frac. So any + * negative number -n.m is encoded as floor(n) + (1 - 0.m). + */ +double +fp1616_to_double(FP1616 in) +{ + double ret; + + ret = (double)(in >> 16); + ret += (double)(in & 0xffff) * (1.0 / (1UL << 16)); /* Optimized: ldexp((double)(in & 0xffff), -16); */ + return ret; +} + +double +fp3232_to_double(FP3232 in) +{ + double ret; + ret = (double)in.integral; + ret += (double)in.frac * (1.0 / (1ULL << 32)); /* Optimized: ldexp((double)in.frac, -32); */ + return ret; +} + + +FP1616 +double_to_fp1616(double in) +{ + FP1616 ret; + int32_t integral; + double tmp; + uint32_t frac_d; + + tmp = floor(in); + integral = (int32_t)tmp; + + tmp = (in - integral) * (1UL << 16); /* Optimized: ldexp(in - integral, 16) */ + frac_d = (uint16_t)tmp; + + ret = integral << 16; + ret |= frac_d & 0xffff; + return ret; +} + +FP3232 +double_to_fp3232(double in) +{ + FP3232 ret; + int32_t integral; + double tmp; + uint32_t frac_d; + + tmp = floor(in); + integral = (int32_t)tmp; + + tmp = (in - integral) * (1ULL << 32); /* Optimized: ldexp(in - integral, 32) */ + frac_d = (uint32_t)tmp; + + ret.integral = integral; + ret.frac = frac_d; + return ret; +} diff --git a/include/inpututils.h b/include/inpututils.h index 47e242d87..2832ed5b1 100644 --- a/include/inpututils.h +++ b/include/inpututils.h @@ -30,6 +30,7 @@ #define INPUTUTILS_H #include "input.h" +#include struct _ValuatorMask { int8_t last_bit; /* highest bit set in mask */ @@ -40,4 +41,9 @@ struct _ValuatorMask { extern void verify_internal_event(const InternalEvent *ev); extern void init_device_event(DeviceEvent *event, DeviceIntPtr dev, Time ms); +FP3232 double_to_fp3232(double in); +FP1616 double_to_fp1616(double in); +double fp1616_to_double(FP1616 in); +double fp3232_to_double(FP3232 in); + #endif diff --git a/test/input.c b/test/input.c index afc4d4d99..64673d25c 100644 --- a/test/input.c +++ b/test/input.c @@ -1462,9 +1462,137 @@ static void input_option_test(void) assert(list == NULL); } +static void +_test_double_fp16_values(double orig_d) +{ + FP1616 first_fp16, final_fp16; + double final_d; + char first_fp16_s[64]; + char final_fp16_s[64]; + + if (orig_d > 0x7FFF) { + printf("Test out of range\n"); + assert(0); + } + + first_fp16 = double_to_fp1616(orig_d); + final_d = fp1616_to_double(first_fp16); + final_fp16 = double_to_fp1616(final_d); + + snprintf(first_fp16_s, sizeof(first_fp16_s), "%d + %u * 2^-16", (first_fp16 & 0xffff0000) >> 16, first_fp16 & 0xffff); + snprintf(final_fp16_s, sizeof(final_fp16_s), "%d + %u * 2^-16", (final_fp16 & 0xffff0000) >> 16, final_fp16 & 0xffff); + + printf("FP16: original double: %f first fp16: %s, re-encoded double: %f, final fp16: %s\n", orig_d, first_fp16_s, final_d, final_fp16_s); + + /* since we lose precision, we only do rough range testing */ + assert(final_d > orig_d - 0.1); + assert(final_d < orig_d + 0.1); + + assert(memcmp(&first_fp16, &final_fp16, sizeof(FP1616)) == 0); + + if (orig_d > 0) + _test_double_fp16_values(-orig_d); +} + +static void +_test_double_fp32_values(double orig_d) +{ + FP3232 first_fp32, final_fp32; + double final_d; + + if (orig_d > 0x7FFFFFFF) { + printf("Test out of range\n"); + assert(0); + } + + first_fp32 = double_to_fp3232(orig_d); + final_d = fp3232_to_double(first_fp32); + final_fp32 = double_to_fp3232(final_d); + + /* { + * char first_fp32_s[64]; + * char final_fp32_s[64]; + * snprintf(first_fp32_s, sizeof(first_fp32_s), "%d + %u * 2^-32", first_fp32.integral, first_fp32.frac); + * snprintf(final_fp32_s, sizeof(final_fp32_s), "%d + %u * 2^-32", first_fp32.integral, final_fp32.frac); + * + * printf("FP32: original double: %f first fp32: %s, re-encoded double: %f, final fp32: %s\n", orig_d, first_fp32_s, final_d, final_fp32_s); + * } + */ + + /* since we lose precision, we only do rough range testing */ + assert(final_d > orig_d - 0.1); + assert(final_d < orig_d + 0.1); + + assert(memcmp(&first_fp32, &final_fp32, sizeof(FP3232)) == 0); + + if (orig_d > 0) + _test_double_fp32_values(-orig_d); +} + +static void +dix_double_fp_conversion(void) +{ + uint32_t i; + printf("Testing double to FP1616/FP3232 conversions\n"); + + _test_double_fp16_values(0); + for (i = 1; i < 0x7FFF; i <<= 1) { + double val; + + val = i; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + /* and some pseudo-random floating points */ + val = i - 0.00382; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.00382; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.05234; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.12342; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.27583; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.50535; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.72342; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + + val = i + 0.80408; + _test_double_fp16_values(val); + _test_double_fp32_values(val); + } + + for (i = 0x7FFFF; i < 0x7FFFFFFF; i <<= 1) { + _test_double_fp32_values(i); + /* and a few more random floating points, obtained + * by faceplanting into the numpad repeatedly */ + _test_double_fp32_values(i + 0.010177); + _test_double_fp32_values(i + 0.213841); + _test_double_fp32_values(i + 0.348720); + _test_double_fp32_values(i + 0.472020); + _test_double_fp32_values(i + 0.572020); + _test_double_fp32_values(i + 0.892929); + } +} int main(int argc, char** argv) { + dix_double_fp_conversion(); dix_input_valuator_masks(); dix_input_attributes(); dix_init_valuators(); -- cgit v1.2.3