diff options
| author | Evan Cheng <evan.cheng@apple.com> | 2008-03-12 07:52:15 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2008-03-12 07:52:15 +0000 |
| commit | 709d19fb6677d8f31c7c9d2457f3647cb09b1941 (patch) | |
| tree | a853da9676a20c9c1110433df083a8bab4dc1837 /include/llvm/CodeGen | |
| parent | 6bb0bd52ecf7481c26cb2d211d6f4f41a6edc855 (diff) | |
| download | external_llvm-709d19fb6677d8f31c7c9d2457f3647cb09b1941.zip external_llvm-709d19fb6677d8f31c7c9d2457f3647cb09b1941.tar.gz external_llvm-709d19fb6677d8f31c7c9d2457f3647cb09b1941.tar.bz2 | |
Document an implementation detail about EXTRACT_SUBREG and INSERT_SUBREG sub-register operand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48283 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/CodeGen')
| -rw-r--r-- | include/llvm/CodeGen/SelectionDAGNodes.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h index b2c354d..49012b4 100644 --- a/include/llvm/CodeGen/SelectionDAGNodes.h +++ b/include/llvm/CodeGen/SelectionDAGNodes.h @@ -320,6 +320,9 @@ namespace ISD { // EXTRACT_SUBREG - This node is used to extract a sub-register value. // This node takes a superreg and a constant sub-register index as operands. + // Note sub-register indices must be increasing. That is, if the + // sub-register index of a 8-bit sub-register is N, then the index for a + // 16-bit sub-register must be at least N+1. EXTRACT_SUBREG, // INSERT_SUBREG - This node is used to insert a sub-register value. |