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| author | Richard Henderson <rth@gcc.gnu.org> | 1998-08-31 03:02:34 -0700 |
|---|---|---|
| committer | Richard Henderson <rth@gcc.gnu.org> | 1998-08-31 03:02:34 -0700 |
| commit | 9953e37587cd491e18b4a3582d7e908bc179596e (patch) | |
| tree | 3fbeb6b326498e7f48e5c5d28b9ee235956d78c2 /gcc/rtl.texi | |
| parent | 6dfdecdb1d8f0ece741e00d187d9cb73d0e9b6ec (diff) | |
| download | gcc-9953e37587cd491e18b4a3582d7e908bc179596e.zip gcc-9953e37587cd491e18b4a3582d7e908bc179596e.tar.gz gcc-9953e37587cd491e18b4a3582d7e908bc179596e.tar.bz2 | |
Document TImode out of 2nd Haifa pass.
From-SVN: r22128
Diffstat (limited to 'gcc/rtl.texi')
| -rw-r--r-- | gcc/rtl.texi | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/gcc/rtl.texi b/gcc/rtl.texi index baba532..b90393e 100644 --- a/gcc/rtl.texi +++ b/gcc/rtl.texi @@ -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: |