Jingyue Wu d4ceea3837 [SLSR] handle candidate form (B + i * S) ...

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235019 91177308-0d34-0410-b5e6-96231b3b80d8

2015-04-15 16:46:13 +00:00

..

X86

[SLSR] handle candidate form (B + i * S)

2015-04-15 16:46:13 +00:00

slsr-add.ll

[SLSR] handle candidate form (B + i * S)

2015-04-15 16:46:13 +00:00

slsr-gep.ll

[SLSR] consider &B[S << i] as &B[(1 << i) * S]

2015-04-06 17:15:48 +00:00

slsr-mul.ll

[SLSR] handle candidate form (B + i * S)

2015-04-15 16:46:13 +00:00