Some phi-nodes are not needed. For example, a phi-node having a
unique value (either a single operand or several but all identical)
can be safely replaced with this unique value. Such trivial ph
nodes are already removed. The object of this series is to detect
and remove more complex trivial phi-nodes: ones where the operands
are themselves defined by a phi-node and when doing the transitive
closure there is only a single independent value. Such phi-nodes
can also be safely be replaced by this unique value.
This series is available for review & testing in the Git repository at:
git://github.com/lucvoo/sparse-dev.git rem-trivial-phi
----------------------------------------------------------------
Luc Van Oostenryck (8):
move DEF_OPCODE() to header file
trivial-phi: add testcase for unneeded trivial phi-nodes
trivial-phi: make clean_up_phi() more sequential
trivial-phi: extract trivial_phi() from clean_up_phi()
trivial-phi: early return
trivial-phi: use a temp var for the real source
trivial-phi: directly return the unique value
trivial-phi: remove more complex trivial phi-nodes
linearize.h | 8 ++++++
simplify.c | 63 ++++++++++++++++++++++++++++-------------
validation/optim/trivial-phis.c | 14 +++++++++
3 files changed, 66 insertions(+), 19 deletions(-)
create mode 100644 validation/optim/trivial-phis.c
