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Differential D107986

[flang] Correct off-by-one error in SET_EXPONENT
ClosedPublic

Authored by klausler on Aug 12 2021, 11:25 AM.

Details

Reviewers
PeteSteinfeld
Commits
rGa05bae6163a3: [flang] Correct off-by-one error in SET_EXPONENT
Summary

SET_EXPONENT is returning values that are too large by a factor of two.

Diff Detail

Event Timeline

klausler created this revision.Aug 12 2021, 11:25 AM
Herald added a subscriber: jdoerfert. · View Herald TranscriptAug 12 2021, 11:25 AM
klausler requested review of this revision.Aug 12 2021, 11:25 AM
Harbormaster completed remote builds in B119299: Diff 366052.Aug 12 2021, 12:15 PM
klausler updated this revision to Diff 366073.Aug 12 2021, 12:27 PM
klausler retitled this revision from [flang] Correct expected unit test results for SET_EXPONENT to [flang] Correct off-by-one error in SET_EXPONENT.
klausler edited the summary of this revision. (Show Details)

Fix both SET_EXPONENT and test.

PeteSteinfeld accepted this revision.Aug 12 2021, 12:48 PM

All builds, tests, and looks good.

This revision is now accepted and ready to land.Aug 12 2021, 12:48 PM
This revision was landed with ongoing or failed builds.Aug 12 2021, 12:51 PM
Closed by commit rGa05bae6163a3: [flang] Correct off-by-one error in SET_EXPONENT (authored by klausler). · Explain Why
This revision was automatically updated to reflect the committed changes.
klausler added a commit: rGa05bae6163a3: [flang] Correct off-by-one error in SET_EXPONENT.
Herald added a project: Restricted Project. · View Herald TranscriptAug 12 2021, 12:51 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
Harbormaster completed remote builds in B119313: Diff 366073.Aug 12 2021, 1:13 PM

Revision Contents

PathSize
flang/
runtime/
2 lines
unittests/
Runtime/
8 lines

Diff 366073

flang/runtime/numeric.cpp

Context not available.
} else if (x == 0) { } else if (x == 0) {
return 0; // 0 -> 0 return 0; // 0 -> 0
} else { } else {
int expo{std::ilogb(x)}; int expo{std::ilogb(x) + 1};
auto ip{static_cast<int>(p - expo)}; auto ip{static_cast<int>(p - expo)};
if (ip != p - expo) { if (ip != p - expo) {
ip = p < 0 ? std::numeric_limits<int>::min() ip = p < 0 ? std::numeric_limits<int>::min()
Context not available.

flang/unittests/Runtime/Numeric.cpp

Context not available.
TEST(Numeric, SetExponent) { TEST(Numeric, SetExponent) {
EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{0}, 0), 0); EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{0}, 0), 0);
EXPECT_EQ(RTNAME(SetExponent8)(Real<8>{0}, 666), 0); EXPECT_EQ(RTNAME(SetExponent8)(Real<8>{0}, 666), 0);
EXPECT_EQ(RTNAME(SetExponent8)(Real<8>{3.0}, 0), 1.5); EXPECT_EQ(RTNAME(SetExponent8)(Real<8>{3.0}, 0), 0.75);
EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, 0), 1.0); EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, 0), 0.5);
EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, 1), 2.0); EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, 1), 1.0);
EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, -1), 0.5); EXPECT_EQ(RTNAME(SetExponent4)(Real<4>{1.0}, -1), 0.25);
EXPECT_TRUE(std::isnan( EXPECT_TRUE(std::isnan(
RTNAME(SetExponent4)(std::numeric_limits<Real<4>>::infinity(), 1))); RTNAME(SetExponent4)(std::numeric_limits<Real<4>>::infinity(), 1)));
EXPECT_TRUE(std::isnan( EXPECT_TRUE(std::isnan(
Context not available.