llvm-project

Commit Graph

Author	SHA1	Message	Date
Matthias Braun	152e7c8b12	VirtRegMap: Replace some identity copies with KILL instructions. An identity COPY like this: %AL = COPY %AL, %EAX<imp-def> has no semantic effect, but encodes liveness information: Further users of %EAX only depend on this instruction even though it does not define the full register. Replace the COPY with a KILL instruction in those cases to maintain this liveness information. (This reverts a small part of r238588 but this time adds a comment explaining why a KILL instruction is useful). llvm-svn: 274952	2016-07-09 00:19:07 +00:00
Simon Pilgrim	ca1da1bf07	[X86][SSE] Improved blend+zero target shuffle combining to use combined shuffle mask directly We currently only combine to blend+zero if the target value type has 8 elements or less, but this was missing a lot of cases where the combined mask had been widened. This change makes it so we use the combined mask to determine the blend value type, allowing us to catch more widened cases. llvm-svn: 272003	2016-06-07 12:20:14 +00:00
Simon Pilgrim	aab59b7a28	[X86][SSE] Some basic tests for variable shuffles We don't really support non-constant shuffle masks, but these tests are for cases where BUILD_VECTOR is made up from vector extracts (as well as undef/zero scalars). llvm-svn: 265045	2016-03-31 20:26:30 +00:00

Author

SHA1

Message

Date

Matthias Braun

152e7c8b12

VirtRegMap: Replace some identity copies with KILL instructions.

An identity COPY like this:
   %AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.

Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).

llvm-svn: 274952

2016-07-09 00:19:07 +00:00

Simon Pilgrim

ca1da1bf07

[X86][SSE] Improved blend+zero target shuffle combining to use combined shuffle mask directly

We currently only combine to blend+zero if the target value type has 8 elements or less, but this was missing a lot of cases where the combined mask had been widened.

This change makes it so we use the combined mask to determine the blend value type, allowing us to catch more widened cases.

llvm-svn: 272003

2016-06-07 12:20:14 +00:00

Simon Pilgrim

aab59b7a28

[X86][SSE] Some basic tests for variable shuffles

We don't really support non-constant shuffle masks, but these tests are for cases where BUILD_VECTOR is made up from vector extracts (as well as undef/zero scalars).

llvm-svn: 265045

2016-03-31 20:26:30 +00:00

3 Commits