If we can show that the base pointers of two GEPs don't alias each other using
precise analysis and the indices and base offset are equal then the two GEPs
also don't alias each other.
This is primarily needed for the follow up patch that analyses NoAlias'ing PHI
nodes.
Part 1/2 of fix for PR13564.
llvm-svn: 163317
The lookup tables did not get built in a deterministic order.
This makes them get built in the order that the corresponding phi nodes
were found.
llvm-svn: 163305
If we have a BUILD_VECTOR that is mostly a constant splat, it is often better to splat that constant then insertelement the non-constant lanes instead of insertelementing every lane from an undef base.
llvm-svn: 163304
This adds a transformation to SimplifyCFG that attemps to turn switch
instructions into loads from lookup tables. It works on switches that
are only used to initialize one or more phi nodes in a common successor
basic block, for example:
int f(int x) {
switch (x) {
case 0: return 5;
case 1: return 4;
case 2: return -2;
case 5: return 7;
case 6: return 9;
default: return 42;
}
This speeds up the code by removing the hard-to-predict jump, and
reduces code size by removing the code for the jump targets.
llvm-svn: 163302
assembler such as shifts greater than 32. In the case
of direct object, the code gen needs to do this lowering
since the assembler is not involved.
With the advent of the llvm-mc assembler, it also needs
to do the same lowering.
This patch makes that specific lowering code accessible
to both the direct object output and the assembler.
This patch does not affect generated output.
llvm-svn: 163287
Now that it is possible to dynamically tie MachineInstr operands,
predicated instructions are possible in SSA form:
%vreg3<def> = SUBri %vreg1, -2147483647, pred:14, pred:%noreg, %opt:%noreg
%vreg4<def,tied1> = MOVCCr %vreg3<tied0>, %vreg1, %pred:12, pred:%CPSR
Becomes a predicated SUBri with a tied imp-use:
SUBri %vreg1, -2147483647, pred:13, pred:%CPSR, opt:%noreg, %vreg1<imp-use,tied0>
This means that any instruction that is safe to move can be folded into
a MOVCC, and the *CC pseudo-instructions are no longer needed.
The test case changes reflect that Thumb2SizeReduce recognizes the
predicated instructions. It didn't understand the pseudos.
llvm-svn: 163274
switch, make sure we include the value for the cases when calculating edge
value from switch to the default destination.
rdar://12241132
llvm-svn: 163270
Previous patch accidentally decided it couldn't convert a VFP to a
NEON instruction after it had already destroyed the old one. Not a
good move.
llvm-svn: 163230
