This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
flow problem avoided, left with global-alloc
- To: gcc at gcc dot gnu dot org
- Subject: flow problem avoided, left with global-alloc
- From: Brad Lucier <lucier at math dot purdue dot edu>
- Date: Sat, 9 Oct 1999 17:11:15 -0500 (EST)
- Cc: hosking at cs dot purdue dot edu, lucier dot feeley at iro dot umontreal dot ca
After thinking about Richard Henderson's comments about flow, and talking
with Feeley, I set a flag to have only one computed goto per
procedure, instead of distributing the computed goto's throughout
the code. (If you want a computed goto, you jump to the "computed
goto basic block".) That cut the compile time and memory requirements
appreciably. Here are the new times for "cc1 -O1 -fPIC -mcpu=supersparc"
with gcc-2.96 19991005:
time in flow: 1.000000 (1%)
time in global-alloc: 48.390000 (71%)
time in flow2: 0.770000 (1%)
By the way, I'm wondering if the flow analysis considers as possible
targets of computed goto's only those labels whose addresses are
taken, rather than all labels.
Brad Lucier