[Lldb-commits] [lldb] 9690b30 - [LLDB] Fix operators <= and >= returning a wrong result when comparing to a floating point NaN (#108060)
via lldb-commits
lldb-commits at lists.llvm.org
Wed Sep 18 05:50:13 PDT 2024
Author: Ilia Kuklin
Date: 2024-09-18T17:50:09+05:00
New Revision: 9690b30ba9acc3deb1068deb37f3b507826b27fe
URL: https://github.com/llvm/llvm-project/commit/9690b30ba9acc3deb1068deb37f3b507826b27fe
DIFF: https://github.com/llvm/llvm-project/commit/9690b30ba9acc3deb1068deb37f3b507826b27fe.diff
LOG: [LLDB] Fix operators <= and >= returning a wrong result when comparing to a floating point NaN (#108060)
Implement operators `<=` and `>=` to explicitly check the comparison
results to be `cmpLessThan` or `cmpEqual` instead of negating the result
of `operators<`.
Fixes #85947
Added:
lldb/test/API/lang/cpp/fpnan/Makefile
lldb/test/API/lang/cpp/fpnan/TestFPNaN.py
lldb/test/API/lang/cpp/fpnan/main.cpp
Modified:
lldb/include/lldb/Utility/Scalar.h
lldb/source/Utility/Scalar.cpp
Removed:
################################################################################
diff --git a/lldb/include/lldb/Utility/Scalar.h b/lldb/include/lldb/Utility/Scalar.h
index 0d8eba3c9726d5..b4b9c7e1895825 100644
--- a/lldb/include/lldb/Utility/Scalar.h
+++ b/lldb/include/lldb/Utility/Scalar.h
@@ -210,6 +210,7 @@ class Scalar {
static PromotionKey GetFloatPromoKey(const llvm::fltSemantics &semantics);
private:
+ friend llvm::APFloat::cmpResult compare(Scalar lhs, Scalar rhs);
friend const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
friend const Scalar operator-(Scalar lhs, Scalar rhs);
friend const Scalar operator/(Scalar lhs, Scalar rhs);
@@ -220,9 +221,9 @@ class Scalar {
friend const Scalar operator^(Scalar lhs, Scalar rhs);
friend const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
friend const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
- friend bool operator==(Scalar lhs, Scalar rhs);
+ friend bool operator==(const Scalar &lhs, const Scalar &rhs);
friend bool operator!=(const Scalar &lhs, const Scalar &rhs);
- friend bool operator<(Scalar lhs, Scalar rhs);
+ friend bool operator<(const Scalar &lhs, const Scalar &rhs);
friend bool operator<=(const Scalar &lhs, const Scalar &rhs);
friend bool operator>(const Scalar &lhs, const Scalar &rhs);
friend bool operator>=(const Scalar &lhs, const Scalar &rhs);
@@ -241,6 +242,7 @@ class Scalar {
// Item 19 of "Effective C++ Second Edition" by Scott Meyers
// Differentiate among members functions, non-member functions, and
// friend functions
+llvm::APFloat::cmpResult compare(Scalar lhs, Scalar rhs);
const Scalar operator+(const Scalar &lhs, const Scalar &rhs);
const Scalar operator-(Scalar lhs, Scalar rhs);
const Scalar operator/(Scalar lhs, Scalar rhs);
@@ -251,9 +253,9 @@ const Scalar operator%(Scalar lhs, Scalar rhs);
const Scalar operator^(Scalar lhs, Scalar rhs);
const Scalar operator<<(const Scalar &lhs, const Scalar &rhs);
const Scalar operator>>(const Scalar &lhs, const Scalar &rhs);
-bool operator==(Scalar lhs, Scalar rhs);
+bool operator==(const Scalar &lhs, const Scalar &rhs);
bool operator!=(const Scalar &lhs, const Scalar &rhs);
-bool operator<(Scalar lhs, Scalar rhs);
+bool operator<(const Scalar &lhs, const Scalar &rhs);
bool operator<=(const Scalar &lhs, const Scalar &rhs);
bool operator>(const Scalar &lhs, const Scalar &rhs);
bool operator>=(const Scalar &lhs, const Scalar &rhs);
diff --git a/lldb/source/Utility/Scalar.cpp b/lldb/source/Utility/Scalar.cpp
index 329f5b6e4b9a5b..f07a9f3bed00c7 100644
--- a/lldb/source/Utility/Scalar.cpp
+++ b/lldb/source/Utility/Scalar.cpp
@@ -852,57 +852,50 @@ llvm::APFloat Scalar::CreateAPFloatFromAPFloat(lldb::BasicType basic_type) {
}
}
-bool lldb_private::operator==(Scalar lhs, Scalar rhs) {
+APFloat::cmpResult lldb_private::compare(Scalar lhs, Scalar rhs) {
// If either entry is void then we can just compare the types
if (lhs.m_type == Scalar::e_void || rhs.m_type == Scalar::e_void)
- return lhs.m_type == rhs.m_type;
+ return lhs.m_type == rhs.m_type ? APFloat::cmpEqual : APFloat::cmpUnordered;
- llvm::APFloat::cmpResult result;
switch (Scalar::PromoteToMaxType(lhs, rhs)) {
case Scalar::e_void:
break;
case Scalar::e_int:
- return lhs.m_integer == rhs.m_integer;
+ if (lhs.m_integer < rhs.m_integer)
+ return APFloat::cmpLessThan;
+ if (lhs.m_integer > rhs.m_integer)
+ return APFloat::cmpGreaterThan;
+ return APFloat::cmpEqual;
case Scalar::e_float:
- result = lhs.m_float.compare(rhs.m_float);
- if (result == llvm::APFloat::cmpEqual)
- return true;
+ return lhs.m_float.compare(rhs.m_float);
}
- return false;
+ return APFloat::cmpUnordered;
}
-bool lldb_private::operator!=(const Scalar &lhs, const Scalar &rhs) {
- return !(lhs == rhs);
+bool lldb_private::operator==(const Scalar &lhs, const Scalar &rhs) {
+ return compare(lhs, rhs) == APFloat::cmpEqual;
}
-bool lldb_private::operator<(Scalar lhs, Scalar rhs) {
- if (lhs.m_type == Scalar::e_void || rhs.m_type == Scalar::e_void)
- return false;
+bool lldb_private::operator!=(const Scalar &lhs, const Scalar &rhs) {
+ return compare(lhs, rhs) != APFloat::cmpEqual;
+}
- llvm::APFloat::cmpResult result;
- switch (Scalar::PromoteToMaxType(lhs, rhs)) {
- case Scalar::e_void:
- break;
- case Scalar::e_int:
- return lhs.m_integer < rhs.m_integer;
- case Scalar::e_float:
- result = lhs.m_float.compare(rhs.m_float);
- if (result == llvm::APFloat::cmpLessThan)
- return true;
- }
- return false;
+bool lldb_private::operator<(const Scalar &lhs, const Scalar &rhs) {
+ return compare(lhs, rhs) == APFloat::cmpLessThan;
}
bool lldb_private::operator<=(const Scalar &lhs, const Scalar &rhs) {
- return !(rhs < lhs);
+ APFloat::cmpResult Res = compare(lhs, rhs);
+ return Res == APFloat::cmpLessThan || Res == APFloat::cmpEqual;
}
bool lldb_private::operator>(const Scalar &lhs, const Scalar &rhs) {
- return rhs < lhs;
+ return compare(lhs, rhs) == APFloat::cmpGreaterThan;
}
bool lldb_private::operator>=(const Scalar &lhs, const Scalar &rhs) {
- return !(lhs < rhs);
+ APFloat::cmpResult Res = compare(lhs, rhs);
+ return Res == APFloat::cmpGreaterThan || Res == APFloat::cmpEqual;
}
bool Scalar::ClearBit(uint32_t bit) {
diff --git a/lldb/test/API/lang/cpp/fpnan/Makefile b/lldb/test/API/lang/cpp/fpnan/Makefile
new file mode 100644
index 00000000000000..99998b20bcb050
--- /dev/null
+++ b/lldb/test/API/lang/cpp/fpnan/Makefile
@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules
diff --git a/lldb/test/API/lang/cpp/fpnan/TestFPNaN.py b/lldb/test/API/lang/cpp/fpnan/TestFPNaN.py
new file mode 100644
index 00000000000000..6093ef91ac1f03
--- /dev/null
+++ b/lldb/test/API/lang/cpp/fpnan/TestFPNaN.py
@@ -0,0 +1,130 @@
+"""
+Test floating point expressions with zero, NaN, dernormalized and infinite
+numbers.
+"""
+
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class FPNaNTestCase(TestBase):
+ def setUp(self):
+ # Call super's setUp().
+ TestBase.setUp(self)
+ # Find the line number to break inside main().
+ self.line = line_number("main.cpp", "// Set break point at this line.")
+
+ def test(self):
+ self.build()
+ exe = self.getBuildArtifact("a.out")
+ self.runCmd("file " + exe, CURRENT_EXECUTABLE_SET)
+
+ # Break inside the main.
+ lldbutil.run_break_set_by_file_and_line(
+ self, "main.cpp", self.line, num_expected_locations=1
+ )
+
+ self.runCmd("run", RUN_SUCCEEDED)
+ # Zero and denorm
+ self.expect(
+ "expr +0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "0"],
+ )
+ self.expect(
+ "expr -0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "0"],
+ )
+ self.expect(
+ "expr 0.0 / 0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "NaN"],
+ )
+ self.expect(
+ "expr 0 / 0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "NaN"],
+ )
+ self.expect(
+ "expr 1 / +0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "+Inf"],
+ )
+ self.expect(
+ "expr 1 / -0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "-Inf"],
+ )
+ self.expect(
+ "expr +0.0 / +0.0 != +0.0 / +0.0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "true"],
+ )
+ self.expect(
+ "expr -1.f * 0",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["float", "-0"],
+ )
+ self.expect(
+ "expr 0x0.123p-1",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["double", "0.0355224609375"],
+ )
+ # NaN
+ self.expect(
+ "expr fnan < fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr fnan <= fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr fnan > fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr fnan >= fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr fnan == fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr fnan != fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "true"],
+ )
+ self.expect(
+ "expr 1.0 <= fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr 1.0f < fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "false"],
+ )
+ self.expect(
+ "expr 1.0f != fnan",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["bool", "true"],
+ )
+ self.expect(
+ "expr (unsigned int) fdenorm",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["int", "0"],
+ )
+ self.expect(
+ "expr (unsigned int) (1.0f + fdenorm)",
+ VARIABLES_DISPLAYED_CORRECTLY,
+ substrs=["int", "1"],
+ )
diff --git a/lldb/test/API/lang/cpp/fpnan/main.cpp b/lldb/test/API/lang/cpp/fpnan/main.cpp
new file mode 100644
index 00000000000000..8bcfebfaea8e1e
--- /dev/null
+++ b/lldb/test/API/lang/cpp/fpnan/main.cpp
@@ -0,0 +1,8 @@
+#include <limits>
+
+int main() {
+ float fnan = std::numeric_limits<float>::quiet_NaN();
+ float fdenorm = std::numeric_limits<float>::denorm_min();
+
+ // Set break point at this line.
+}
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