[Fixed Point] Add floating point methods to APFixedPoint.
This adds methods to APFixedPoint for converting to and from
floating point values.
Differential Revision: https://reviews.llvm.org/D85961
diff --git a/llvm/unittests/ADT/APFixedPointTest.cpp b/llvm/unittests/ADT/APFixedPointTest.cpp
index 02e80ca..53fa1cd 100644
--- a/llvm/unittests/ADT/APFixedPointTest.cpp
+++ b/llvm/unittests/ADT/APFixedPointTest.cpp
@@ -7,13 +7,15 @@
//===----------------------------------------------------------------------===//
#include "llvm/ADT/APFixedPoint.h"
+#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APSInt.h"
#include "gtest/gtest.h"
using llvm::APFixedPoint;
-using llvm::FixedPointSemantics;
+using llvm::APFloat;
using llvm::APInt;
using llvm::APSInt;
+using llvm::FixedPointSemantics;
namespace {
@@ -641,4 +643,282 @@
4294967295ULL << 32);
}
+enum OvfKind { MinSat, MaxSat };
+
+void CheckFloatToFixedConversion(APFloat &Val, const FixedPointSemantics &Sema,
+ int64_t ExpectedNonSat) {
+ bool Ovf;
+ ASSERT_EQ(APFixedPoint::getFromFloatValue(Val, Sema, &Ovf).getValue(),
+ ExpectedNonSat);
+ ASSERT_EQ(Ovf, false);
+ ASSERT_EQ(
+ APFixedPoint::getFromFloatValue(Val, Saturated(Sema), &Ovf).getValue(),
+ ExpectedNonSat);
+ ASSERT_EQ(Ovf, false);
+}
+
+void CheckFloatToFixedConversion(APFloat &Val, const FixedPointSemantics &Sema,
+ OvfKind ExpectedOvf) {
+ bool Ovf;
+ (void)APFixedPoint::getFromFloatValue(Val, Sema, &Ovf);
+ ASSERT_EQ(Ovf, true);
+ ASSERT_EQ(
+ APFixedPoint::getFromFloatValue(Val, Saturated(Sema), &Ovf).getValue(),
+ (ExpectedOvf == MinSat ? APFixedPoint::getMin(Sema)
+ : APFixedPoint::getMax(Sema))
+ .getValue());
+ ASSERT_EQ(Ovf, false);
+}
+
+TEST(FixedPoint, FloatToFixed) {
+ APFloat Val(0.0f);
+
+ // Simple exact fraction
+ Val = APFloat(0.75f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), 3ULL << 5);
+ CheckFloatToFixedConversion(Val, getAccumSema(), 3ULL << 13);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), 3ULL << 29);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), 3ULL << 6);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), 3ULL << 14);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), 3ULL << 30);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), 3ULL << 5);
+ CheckFloatToFixedConversion(Val, getFractSema(), 3ULL << 13);
+ CheckFloatToFixedConversion(Val, getLFractSema(), 3ULL << 29);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), 3ULL << 6);
+ CheckFloatToFixedConversion(Val, getUFractSema(), 3ULL << 14);
+ CheckFloatToFixedConversion(Val, getULFractSema(), 3ULL << 30);
+
+ // Simple negative exact fraction
+ Val = APFloat(-0.75f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), -3ULL << 5);
+ CheckFloatToFixedConversion(Val, getAccumSema(), -3ULL << 13);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), -3ULL << 29);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), MinSat);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), -3ULL << 5);
+ CheckFloatToFixedConversion(Val, getFractSema(), -3ULL << 13);
+ CheckFloatToFixedConversion(Val, getLFractSema(), -3ULL << 29);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getUFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getULFractSema(), MinSat);
+
+ // Highly precise fraction
+ Val = APFloat(0.999999940395355224609375f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), 0x7FULL);
+ CheckFloatToFixedConversion(Val, getAccumSema(), 0x7FFFULL);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), 0xFFFFFFULL << 7);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), 0xFFULL);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), 0xFFFFULL);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), 0xFFFFFFULL << 8);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), 0x7FULL);
+ CheckFloatToFixedConversion(Val, getFractSema(), 0x7FFFULL);
+ CheckFloatToFixedConversion(Val, getLFractSema(), 0xFFFFFFULL << 7);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), 0xFFULL);
+ CheckFloatToFixedConversion(Val, getUFractSema(), 0xFFFFULL);
+ CheckFloatToFixedConversion(Val, getULFractSema(), 0xFFFFFFULL << 8);
+
+ // Integral and fraction
+ Val = APFloat(17.99609375f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), 0x11FFULL >> 1);
+ CheckFloatToFixedConversion(Val, getAccumSema(), 0x11FFULL << 7);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), 0x11FFULL << 23);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), 0x11FFULL);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), 0x11FFULL << 8);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), 0x11FFULL << 24);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getLFractSema(), MaxSat);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getUFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getULFractSema(), MaxSat);
+
+ // Negative integral and fraction
+ Val = APFloat(-17.99609375f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), -0x11FELL >> 1);
+ CheckFloatToFixedConversion(Val, getAccumSema(), -0x11FFULL << 7);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), -0x11FFULL << 23);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), MinSat);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getLFractSema(), MinSat);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getUFractSema(), MinSat);
+ CheckFloatToFixedConversion(Val, getULFractSema(), MinSat);
+
+ // Very large value
+ Val = APFloat(1.0e38f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getAccumSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), MaxSat);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), MaxSat);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getLFractSema(), MaxSat);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getUFractSema(), MaxSat);
+ CheckFloatToFixedConversion(Val, getULFractSema(), MaxSat);
+
+ // Very small value
+ Val = APFloat(1.0e-38f);
+ CheckFloatToFixedConversion(Val, getSAccumSema(), 0);
+ CheckFloatToFixedConversion(Val, getAccumSema(), 0);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), 0);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), 0);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), 0);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), 0);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), 0);
+ CheckFloatToFixedConversion(Val, getFractSema(), 0);
+ CheckFloatToFixedConversion(Val, getLFractSema(), 0);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), 0);
+ CheckFloatToFixedConversion(Val, getUFractSema(), 0);
+ CheckFloatToFixedConversion(Val, getULFractSema(), 0);
+
+ // Half conversion
+ Val = APFloat(0.99951171875f);
+ bool Ignored;
+ Val.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &Ignored);
+
+ CheckFloatToFixedConversion(Val, getSAccumSema(), 0x7FULL);
+ CheckFloatToFixedConversion(Val, getAccumSema(), 0x7FFULL << 4);
+ CheckFloatToFixedConversion(Val, getLAccumSema(), 0x7FFULL << 20);
+
+ CheckFloatToFixedConversion(Val, getUSAccumSema(), 0xFFULL);
+ CheckFloatToFixedConversion(Val, getUAccumSema(), 0xFFEULL << 4);
+ CheckFloatToFixedConversion(Val, getULAccumSema(), 0xFFEULL << 20);
+
+ CheckFloatToFixedConversion(Val, getSFractSema(), 0x7FULL);
+ CheckFloatToFixedConversion(Val, getFractSema(), 0x7FFULL << 4);
+ CheckFloatToFixedConversion(Val, getLFractSema(), 0x7FFULL << 20);
+
+ CheckFloatToFixedConversion(Val, getUSFractSema(), 0xFFULL);
+ CheckFloatToFixedConversion(Val, getUFractSema(), 0xFFEULL << 4);
+ CheckFloatToFixedConversion(Val, getULFractSema(), 0xFFEULL << 20);
+}
+
+void CheckFixedToFloatConversion(int64_t Val, const FixedPointSemantics &Sema,
+ float Result) {
+ APFixedPoint FXVal(Val, Sema);
+ APFloat APRes(Result);
+ ASSERT_EQ(FXVal.convertToFloat(APFloat::IEEEsingle()), APRes);
+}
+
+void CheckFixedToHalfConversion(int64_t Val, const FixedPointSemantics &Sema,
+ float Result) {
+ APFixedPoint FXVal(Val, Sema);
+ APFloat APRes(Result);
+ bool Ignored;
+ APRes.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &Ignored);
+ ASSERT_EQ(FXVal.convertToFloat(APFloat::IEEEhalf()), APRes);
+}
+
+TEST(FixedPoint, FixedToFloat) {
+ int64_t Val = 0x1ULL;
+ CheckFixedToFloatConversion(Val, getSAccumSema(), 0.0078125f);
+ CheckFixedToFloatConversion(Val, getFractSema(), 0.000030517578125f);
+ CheckFixedToFloatConversion(Val, getAccumSema(), 0.000030517578125f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ 0.0000000004656612873077392578125f);
+
+ CheckFixedToFloatConversion(Val, getUSAccumSema(), 0.00390625f);
+ CheckFixedToFloatConversion(Val, getUFractSema(), 0.0000152587890625f);
+ CheckFixedToFloatConversion(Val, getUAccumSema(), 0.0000152587890625f);
+ CheckFixedToFloatConversion(Val, getULFractSema(),
+ 0.00000000023283064365386962890625f);
+
+ Val = 0x7FULL;
+ CheckFixedToFloatConversion(Val, getSAccumSema(), 0.9921875f);
+ CheckFixedToFloatConversion(Val, getFractSema(), 0.003875732421875f);
+ CheckFixedToFloatConversion(Val, getAccumSema(), 0.003875732421875f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ 0.0000000591389834880828857421875f);
+
+ CheckFixedToFloatConversion(Val, getUSAccumSema(), 0.49609375f);
+ CheckFixedToFloatConversion(Val, getUFractSema(), 0.0019378662109375f);
+ CheckFixedToFloatConversion(Val, getUAccumSema(), 0.0019378662109375f);
+ CheckFixedToFloatConversion(Val, getULFractSema(),
+ 0.00000002956949174404144287109375f);
+
+ Val = -0x1ULL;
+ CheckFixedToFloatConversion(Val, getSAccumSema(), -0.0078125f);
+ CheckFixedToFloatConversion(Val, getFractSema(), -0.000030517578125f);
+ CheckFixedToFloatConversion(Val, getAccumSema(), -0.000030517578125f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ -0.0000000004656612873077392578125f);
+
+
+ CheckFixedToFloatConversion(-0x80ULL, getSAccumSema(), -1.0f);
+ CheckFixedToFloatConversion(-0x8000ULL, getFractSema(), -1.0f);
+ CheckFixedToFloatConversion(-0x8000ULL, getAccumSema(), -1.0f);
+ CheckFixedToFloatConversion(-0x80000000ULL, getLFractSema(), -1.0f);
+
+ Val = 0xAFAULL;
+ CheckFixedToFloatConversion(Val, getSAccumSema(), 21.953125f);
+ CheckFixedToFloatConversion(Val, getFractSema(), 0.08575439453125f);
+ CheckFixedToFloatConversion(Val, getAccumSema(), 0.08575439453125f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ 0.000001308508217334747314453125f);
+
+ CheckFixedToFloatConversion(Val, getUSAccumSema(), 10.9765625f);
+ CheckFixedToFloatConversion(Val, getUFractSema(), 0.042877197265625f);
+ CheckFixedToFloatConversion(Val, getUAccumSema(), 0.042877197265625f);
+ CheckFixedToFloatConversion(Val, getULFractSema(),
+ 0.0000006542541086673736572265625f);
+
+ Val = -0xAFAULL;
+ CheckFixedToFloatConversion(Val, getSAccumSema(), -21.953125f);
+ CheckFixedToFloatConversion(Val, getFractSema(), -0.08575439453125f);
+ CheckFixedToFloatConversion(Val, getAccumSema(), -0.08575439453125f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ -0.000001308508217334747314453125f);
+
+ Val = 0x40000080ULL;
+ CheckFixedToFloatConversion(Val, getAccumSema(), 32768.00390625f);
+ CheckFixedToFloatConversion(Val, getLFractSema(),
+ 0.500000059604644775390625f);
+
+ CheckFixedToFloatConversion(Val, getUAccumSema(), 16384.001953125f);
+ CheckFixedToFloatConversion(Val, getULFractSema(),
+ 0.2500000298023223876953125f);
+
+ Val = 0x40000040ULL;
+ CheckFixedToFloatConversion(Val, getAccumSema(), 32768.0f);
+ CheckFixedToFloatConversion(Val, getLFractSema(), 0.5f);
+
+ CheckFixedToFloatConversion(Val, getUAccumSema(), 16384.0f);
+ CheckFixedToFloatConversion(Val, getULFractSema(), 0.25f);
+
+ Val = 0x7FF0ULL;
+ CheckFixedToHalfConversion(Val, getAccumSema(), 0.99951171875f);
+ CheckFixedToHalfConversion(Val, getLFractSema(), 0.000015251338481903076171875f);
+
+ CheckFixedToHalfConversion(Val, getUAccumSema(), 0.499755859375f);
+ CheckFixedToHalfConversion(Val, getULFractSema(), 0.0000076256692409515380859375f);
+}
+
} // namespace