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authorDaniel Sanders <daniel.sanders@imgtec.com>2015-07-13 09:24:21 +0000
committerDaniel Sanders <daniel.sanders@imgtec.com>2015-07-13 09:24:21 +0000
commitddb76b4462d5afc90fe5bc620c283bf884afcf8b (patch)
tree5a9ed9396e47a24889e882ffc4981ff66ec28c43 /docs
parent8e7e3650af1076daa6a755dc9b54bc8be6266be5 (diff)
[mips] Explained the 'w' modifier in the Inline Assembler documentation.
It exists for compatibility with GCC which requires it to print MSA registers for the 'f' constraint. Although LLVM doesn't need it, the 'w' modifier should still be used for portability between the two compilers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242015 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
-rw-r--r--docs/LangRef.rst7
1 files changed, 5 insertions, 2 deletions
diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index 48771c211c1..e7d6f67c939 100644
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -3200,7 +3200,8 @@ MIPS:
``sc`` instruction on the given subtarget (details vary).
- ``r``, ``d``, ``y``: A 32 or 64-bit GPR register.
- ``f``: A 32 or 64-bit FPU register (``F0-F31``), or a 128-bit MSA register
- (``W0-W31``).
+ (``W0-W31``). In the case of MSA registers, it is recommended to use the ``w``
+ argument modifier for compatibility with GCC.
- ``c``: A 32-bit or 64-bit GPR register suitable for indirect jump (always
``25``).
- ``l``: The ``lo`` register, 32 or 64-bit.
@@ -3409,7 +3410,9 @@ MIPS:
second word of a double-word memory operand. (On a big-endian system, ``D`` is
equivalent to ``L``, and on little-endian system, ``D`` is equivalent to
``M``.)
-- ``w``: No effect.
+- ``w``: No effect. Provided for compatibility with GCC which requires this
+ modifier in order to print MSA registers (``W0-W31``) with the ``f``
+ constraint.
NVPTX: