[LLDB] Add APFloat helper functions to Scalar class.

[cmtice]

This adds the ability to create a Scalar from an APFloat, and to create an APFloat from an APSInt or another APFloat.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: None (cmtice)

Changes

This adds the ability to create a Scalar from an APFloat, and to create an APFloat from an APSInt or another APFloat.

---

Full diff: https://github.com/llvm/llvm-project/pull/86862.diff

2 Files Affected:

• (modified) lldb/include/lldb/Utility/Scalar.h (+6)
• (modified) lldb/source/Utility/Scalar.cpp (+42)

diff --git a/lldb/include/lldb/Utility/Scalar.h b/lldb/include/lldb/Utility/Scalar.h
index 8e087a5ddeb855..d5e70fdf203001 100644
--- a/lldb/include/lldb/Utility/Scalar.h
+++ b/lldb/include/lldb/Utility/Scalar.h
@@ -71,6 +71,8 @@ class Scalar {
       : m_type(e_int), m_integer(std::move(v), false), m_float(0.0f) {}
   Scalar(llvm::APSInt v)
       : m_type(e_int), m_integer(std::move(v)), m_float(0.0f) {}
+  Scalar(llvm::APFloat v)
+      : m_integer(0), m_float(v) {}
 
   bool SignExtend(uint32_t bit_pos);
 
@@ -186,6 +188,10 @@ class Scalar {
   Status SetValueFromData(const DataExtractor &data, lldb::Encoding encoding,
                           size_t byte_size);
 
+  llvm::APFloat CreateAPFloatFromAPSInt(lldb::BasicType basic_type);
+
+  llvm::APFloat CreateAPFloatFromAPFloat(lldb::BasicType basic_type);
+
 protected:
   Scalar::Type m_type = e_void;
   llvm::APSInt m_integer;
diff --git a/lldb/source/Utility/Scalar.cpp b/lldb/source/Utility/Scalar.cpp
index 5ad68065bce1b7..afcb204d8f95a5 100644
--- a/lldb/source/Utility/Scalar.cpp
+++ b/lldb/source/Utility/Scalar.cpp
@@ -813,6 +813,48 @@ bool Scalar::ExtractBitfield(uint32_t bit_size, uint32_t bit_offset) {
   return false;
 }
 
+llvm::APFloat Scalar::CreateAPFloatFromAPSInt(lldb::BasicType basic_type) {
+  switch (basic_type) {
+    case lldb::eBasicTypeFloat:
+      return llvm::APFloat(m_integer.isSigned()
+                           ? llvm::APIntOps::RoundSignedAPIntToFloat(m_integer)
+                           : llvm::APIntOps::RoundAPIntToFloat(m_integer));
+    case lldb::eBasicTypeDouble:
+      // No way to get more precision at the moment.
+    case lldb::eBasicTypeLongDouble:
+      return llvm::APFloat(m_integer.isSigned()
+                               ? llvm::APIntOps::RoundSignedAPIntToDouble(
+                                   m_integer)
+                               : llvm::APIntOps::RoundAPIntToDouble(m_integer));
+    default:
+      const llvm::fltSemantics &sem = APFloat::IEEEsingle();
+      return llvm::APFloat::getNaN(sem);
+  }
+}
+
+llvm::APFloat Scalar::CreateAPFloatFromAPFloat(lldb::BasicType basic_type) {
+  switch (basic_type) {
+    case lldb::eBasicTypeFloat: {
+      bool loses_info;
+      m_float.convert(llvm::APFloat::IEEEsingle(),
+                      llvm::APFloat::rmNearestTiesToEven, &loses_info);
+      return m_float;
+    }
+    case lldb::eBasicTypeDouble:
+      // No way to get more precision at the moment.
+    case lldb::eBasicTypeLongDouble: {
+      bool loses_info;
+      m_float.convert(llvm::APFloat::IEEEdouble(),
+                    llvm::APFloat::rmNearestTiesToEven, &loses_info);
+      return m_float;
+    }
+    default:
+      const llvm::fltSemantics &sem = APFloat::IEEEsingle();
+      return llvm::APFloat::getNaN(sem);
+  }
+}
+
+
 bool lldb_private::operator==(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)

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[bulbazord]

Could you add a test for these new methods in unittests/Utility/ScalarTest.cpp?

[cmtice]

Could you add a test for these new methods in unittests/Utility/ScalarTest.cpp?

Done. :-)

[bulbazord]

Could you add a test for these new methods in unittests/Utility/ScalarTest.cpp?

Done. :-)

Thank you! :)