[Lldb-commits] [lldb] r237900 - Add float/double return value handling to SysV-arm ABI

[Tamas Berghammer]

Author: tberghammer
Date: Thu May 21 08:34:46 2015
New Revision: 237900

URL: http://llvm.org/viewvc/llvm-project?rev=237900&view=rev
Log:
Add float/double return value handling to SysV-arm ABI

This is neccessary for evaluating expressions with float/double return
value and for displaying float/double return values in case of a thread
step out.

Differential revision: http://reviews.llvm.org/D9907

Modified:
    lldb/trunk/source/Plugins/ABI/SysV-arm/ABISysV_arm.cpp

Modified: lldb/trunk/source/Plugins/ABI/SysV-arm/ABISysV_arm.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ABI/SysV-arm/ABISysV_arm.cpp?rev=237900&r1=237899&r2=237900&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ABI/SysV-arm/ABISysV_arm.cpp (original)
+++ lldb/trunk/source/Plugins/ABI/SysV-arm/ABISysV_arm.cpp Thu May 21 08:34:46 2015
@@ -420,6 +420,8 @@ ABISysV_arm::GetReturnValueObjectImpl (T
         return return_valobj_sp;
         
     bool is_signed;
+    bool is_complex;
+    uint32_t float_count;
     
     // Get the pointer to the first stack argument so we have a place to start 
     // when reading data
@@ -470,6 +472,41 @@ ABISysV_arm::GetReturnValueObjectImpl (T
         uint32_t ptr = thread.GetRegisterContext()->ReadRegisterAsUnsigned(r0_reg_info, 0) & UINT32_MAX;
         value.GetScalar() = ptr;
     }
+    else if (clang_type.IsFloatingPointType(float_count, is_complex))
+    {
+        if (float_count == 1 && !is_complex)
+        {
+            size_t bit_width = clang_type.GetBitSize(&thread);
+            switch (bit_width)
+            {
+                default:
+                    return return_valobj_sp;
+                case 64:
+                {
+                    static_assert(sizeof(double) == sizeof(uint64_t), "");
+                    const RegisterInfo *r1_reg_info = reg_ctx->GetRegisterInfo(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_ARG2);
+                    uint64_t raw_value;
+                    raw_value = reg_ctx->ReadRegisterAsUnsigned(r0_reg_info, 0) & UINT32_MAX;
+                    raw_value |= ((uint64_t)(reg_ctx->ReadRegisterAsUnsigned(r1_reg_info, 0) & UINT32_MAX)) << 32;
+                    value.GetScalar() = *reinterpret_cast<double*>(&raw_value);
+                    break;
+                }
+                case 16: // Half precision returned after a conversion to single precision
+                case 32:
+                {
+                    static_assert(sizeof(float) == sizeof(uint32_t), "");
+                    uint32_t raw_value = reg_ctx->ReadRegisterAsUnsigned(r0_reg_info, 0) & UINT32_MAX;
+                    value.GetScalar() = *reinterpret_cast<float*>(&raw_value);
+                    break;
+                }
+            }
+        }
+        else
+        {
+            // not handled yet
+            return return_valobj_sp;
+        }
+    }
     else
     {
         // not handled yet