Constant. This lets ConstantInts be handled as SCEVConstant instead
of SCEVUnknown, as getUnknown no longer has special-case code for
ConstantInt and friends. This usually doesn't affect the final
output, since the constants end up getting folded later, but it
does make intermediate expressions more obvious in many cases.
llvm-svn: 74459
an individual exhaustive evaluation reflects only the exit value
implied by an individual exit, which may differ from the actual
exit value of the loop if there are other exits. This fixes PR4477.
llvm-svn: 74447
Also don't call finalizers for LoopPass if initialization was not called.
Add a unittest that tests that these methods are called, in the proper
order, and the correct number of times.
llvm-svn: 74438
fence-atomic-fence down to just the atomic op. This is possible thanks to
X86's relatively strong memory model, which guarantees that locked instructions
(which are used to implement atomics) are implicit fences.
llvm-svn: 74435
After much back and forth, I decided to deviate from ARM design and split LDR into 4 instructions (r + imm12, r + imm8, r + r << imm12, constantpool). The advantage of this is 1) it follows the latest ARM technical manual, and 2) makes it easier to reduce the width of the instruction later. The down side is this creates more inconsistency between the two sub-targets. We should split ARM LDR instruction in a similar fashion later. I've added a README entry for this.
llvm-svn: 74420
Implemented by making lib/CompilerDriver a shared library that holds all the
global static data (CommandLine options, plugin registry) that we unfortunately
have to live with.
llvm-svn: 74417
when one of them can be converted to a trivial icmp and conditional
branch.
This addresses what is essentially a phase ordering problem.
SimplifyCFG knows how to do this transformation, but it doesn't do so
if the primary block has any instructions in it other than an icmp and
a branch. In the given testcase, the block contains other instructions,
however they are loop-invariant and can be hoisted. SimplifyCFG doesn't
have LoopInfo though, so it can't hoist them. And, it's important that
the blocks be merged before LoopRotation, as it doesn't support
multiple-exit loops.
llvm-svn: 74396
