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Diffstat (limited to 'docs/LangRef.rst')
| -rw-r--r-- | docs/LangRef.rst | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/docs/LangRef.rst b/docs/LangRef.rst index 4d006f135c..4eecd15a6f 100644 --- a/docs/LangRef.rst +++ b/docs/LangRef.rst @@ -127,7 +127,8 @@ lexical features of LLVM: #. Comments are delimited with a '``;``' and go until the end of line. #. Unnamed temporaries are created when the result of a computation is not assigned to a named value. -#. Unnamed temporaries are numbered sequentially +#. Unnamed temporaries are numbered sequentially (using a per-function + incrementing counter, starting with 0). It also shows a convention that we follow in this document. When demonstrating instructions, we will follow an instruction with a comment @@ -563,7 +564,11 @@ A function definition contains a list of basic blocks, forming the CFG start with a label (giving the basic block a symbol table entry), contains a list of instructions, and ends with a :ref:`terminator <terminators>` instruction (such as a branch or function -return). +return). If explicit label is not provided, a block is assigned an +implicit numbered label, using a next value from the same counter as used +for unnamed temporaries (:ref:`see above<identifiers>`). For example, if a +function entry block does not have explicit label, it will be assigned +label "%0", then first unnamed temporary in that block will be "%1", etc. The first basic block in a function is special in two ways: it is immediately executed on entrance to the function, and it is not allowed |