[Lldb-commits] [PATCH] D17897: Support floating point values in 128-bit SSE vector registers

[Adrian Prantl via lldb-commits]

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The System-V x86_64 ABI requires floating point values to be passed in 128-but SSE vector registers (xmm0, ...).
When printing such a variable this currently yields an <invalid load address>.

This patch makes LLDB's DWARF expression evaluator accept 128-bit registers as scalars. It also relaxes the check that the size of the result of the DWARF expression be equal to the size of the variable to a greater-than. DWARF defers to the ABI how smaller values are being placed in a larger register.

Implementation note: I found the code in Value::SetContext() that changes the m_value_type after the fact to be questionable. I added a sanity check that the Value's memory buffer has indeed been written to (this is necessary, because we may have a scalar value in a vector register), but really I feel like this is the wrong place to be setting it.

<rdar://problem/24944340>

Repository:
  rL LLVM

http://reviews.llvm.org/D17897

Files:
  include/lldb/Core/Value.h
  packages/Python/lldbsuite/test/lang/c/register_variables/TestRegisterVariables.py
  packages/Python/lldbsuite/test/lang/c/register_variables/test.c
  source/Core/RegisterValue.cpp
  source/Expression/Materializer.cpp

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