[Lldb-commits] [lldb] [LLDB] Add APFloat helper functions to Scalar class. (PR #86862)

[via lldb-commits]

https://github.com/cmtice created https://github.com/llvm/llvm-project/pull/86862

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

>From 03ef6db02f49ab4cc4f63b32553015b4f3801b5b Mon Sep 17 00:00:00 2001
From: Caroline Tice <cmtice at google.com>
Date: Wed, 27 Mar 2024 10:09:45 -0700
Subject: [PATCH] [LLDB] Add APFloat helper functions to Scalar class.

This adds the ability to create a Scalar from an APFloat, and to
create an APFloat from an APSInt or another APFloat.
---
 lldb/include/lldb/Utility/Scalar.h |  6 +++++
 lldb/source/Utility/Scalar.cpp     | 42 ++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

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)