Document TImode out of 2nd Haifa pass.

From-SVN: r22128
This commit is contained in:
Richard Henderson 1998-08-31 03:02:34 -07:00
parent 6dfdecdb1d
commit 9953e37587
1 changed files with 12 additions and 3 deletions

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@ -2368,14 +2368,23 @@ Appears following each call to @code{setjmp} or a related function.
These codes are printed symbolically when they appear in debugging dumps.
@end table
@cindex @code{TImode}, in @code{insn}
@cindex @code{HImode}, in @code{insn}
@cindex @code{QImode}, in @code{insn}
The machine mode of an insn is normally @code{VOIDmode}, but some
phases use the mode for various purposes; for example, the reload pass
sets it to @code{HImode} if the insn needs reloading but not register
elimination and @code{QImode} if both are required. The common
subexpression elimination pass sets the mode of an insn to @code{QImode}
when it is the first insn in a block that has already been processed.
elimination and @code{QImode} if both are required.
The common subexpression elimination pass sets the mode of an insn to
@code{QImode} when it is the first insn in a block that has already
been processed.
The second Haifa scheduling pass, for targets that can multiple issue,
sets the mode of an insn to @code{TImode} when it is believed that the
instruction begins an issue group. That is, when the instruction
cannot issue simultaneously with the previous. This may be relied on
by later passes, in particular machine-dependant reorg.
Here is a table of the extra fields of @code{insn}, @code{jump_insn}
and @code{call_insn} insns: