Summary:
Consider (B | i) * S as (B + i) * S if B and i have no bits set in
common.
Test Plan: @or in slsr-mul.ll
Reviewers: broune, meheff
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9788
llvm-svn: 237456
Summary:
After we rewrite a candidate, the instructions used by the old form may
become unused. This patch cleans up these unused instructions so that we
needn't run DCE after SLSR.
Test Plan: removed -dce in all the SLSR tests
Reviewers: broune, meheff
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D9101
llvm-svn: 235410
Summary:
With this patch, SLSR may rewrite
S1: X = B + i * S
S2: Y = B + i' * S
to
S2: Y = X + (i' - i) * S
A secondary improvement: if (i' - i) is a power of 2, emit Y as X + (S << log(i' - i)). (S << log(i' -i)) is in a canonical form and thus more likely GVN'ed than (i' - i) * S.
Test Plan: slsr-add.ll
Reviewers: hfinkel, sanjoy, meheff, broune, eliben
Reviewed By: eliben
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8983
llvm-svn: 235019
Summary:
This patch enhances SLSR to handle another candidate form &B[i * S]. If
we found two candidates
S1: X = &B[i * S]
S2: Y = &B[i' * S]
and S1 dominates S2, we can replace S2 with
Y = &X[(i' - i) * S]
Test Plan:
slsr-gep.ll
X86/no-slsr.ll: verify that we do not run SLSR on GEPs that already fit into
an addressing mode
Reviewers: eliben, atrick, meheff, hfinkel
Reviewed By: hfinkel
Subscribers: sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D7459
llvm-svn: 233286
Jingyue Wu