If we were to unfold these, the load size would be increased to the register size. This is not safe to do since the enlarged load can do things like cross a page boundary into a page that doesn't exist.
I probably missed some instructions, but this should be a large portion of them.
llvm-svn: 288001
Most of these are the SSE4.1 PMOVZX/PMOVSX instructions which all read less than 128-bits. The only other was PMOVUPD which by definition is an unaligned load.
llvm-svn: 287991
Summary: When selectScalarSSELoad is looking for a scalar_to_vector of a scalar load, it makes sure the load is only used by the scalar_to_vector. But it doesn't make sure the scalar_to_vector is only used once. This can cause the same load to be folded multiple times. This can be bad for performance. This also causes the chain output to be duplicated, but not connected to anything so chain dependencies will not be satisfied.
Reviewers: RKSimon, zvi, delena, spatel
Subscribers: andreadb, llvm-commits
Differential Revision: https://reviews.llvm.org/D26790
llvm-svn: 287983
There are other spots where we can use this; we're currently dropping
metadata in some places, and there are proposed changes where we will
want to propagate metadata.
IRBuilder's CreateSelect() already has a parameter like this, so this
change makes the regular 'Create' API line up with that.
llvm-svn: 287976
The W bit distinquishes which operand is the memory operand. But if the mod bits are 3 then the memory operand is a register and there are two possible encodings. We already did this correctly for several other XOP instructions.
llvm-svn: 287961
Not sure this is truly needed but we had the floating point equivalents, the aligned equivalents, and the EVEX equivalents. So this just makes it complete.
llvm-svn: 287960
Summary:
Shuffle lowering may have widened the element size of a i32 shuffle to i64 before selecting X86ISD::SHUF128. If this shuffle was used by a vselect this can prevent us from selecting masked operations.
This patch detects this and changes the element size to match the vselect.
I don't handle changing integer to floating point or vice versa as its not clear if its better to push such a bitcast to the inputs of the shuffle or to the user of the vselect. So I'm ignoring that case for now.
Reviewers: delena, zvi, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27087
llvm-svn: 287939
Summary:
The iterative algorithm for Loop Unswitching may render some of the branches unreachable in the unswitched loops.
Given the exponential nature of the algorithm, this is quite an overhead.
This patch fixes this problem by selectively unswitching only those branches within a loop that are reachable from the loop header.
Reviewers: Michael Zolothukin, Anna Thomas, Weiming Zhao.
Subscribers: llvm-commits.
Differential Revision: http://reviews.llvm.org/D26299
llvm-svn: 287925
This patch corrects the behaviour of code such as:
.local foo
jal foo
foo:
to use the correct jal expansion when writing ELF files.
Patch by: Daniel Sanders
Reviewers: zoran.jovanovic, seanbruno, vkalintiris
Differential Revision: https://reviews.llvm.org/D24722
llvm-svn: 287918
