Split memset formation logic out into its own
"tryMergingIntoMemset" helper function.

llvm-svn: 123081

Two minor fixes:  1.  Put integral_constant conversion to integral in even without constexpr support.  2.  Add ios_base to <iosfwd>.  The latter is being tracked by LWG 2026.

llvm-svn: 123080

to be foldable into an uncond branch.  When this happens, we can make a
much simpler CFG for the loop, which is important for nested loop cases
where we want the outer loop to be aggressively optimized.

Handle this case more aggressively.  For example, previously on
phi-duplicate.ll we would get this:


define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  %cmp1 = icmp slt i64 1, 1000
  br i1 %cmp1, label %bb.nph, label %for.end

bb.nph:                                           ; preds = %entry
  br label %for.body

for.body:                                         ; preds = %bb.nph, %for.cond
  %j.02 = phi i64 [ 1, %bb.nph ], [ %inc, %for.cond ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.02
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.02, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.02
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.02, 1
  br label %for.cond

for.cond:                                         ; preds = %for.body
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge

for.cond.for.end_crit_edge:                       ; preds = %for.cond
  br label %for.end

for.end:                                          ; preds = %for.cond.for.end_crit_edge, %entry
  ret void
}

Now we get the much nicer:

define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %j.01 = phi i64 [ 1, %entry ], [ %inc, %for.body ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.01
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.01, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.01
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.01, 1
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.end

for.end:                                          ; preds = %for.body
  ret void
}

With all of these recent changes, we are now able to compile:

void foo(char *X) {
 for (int i = 0; i != 100; ++i) 
   for (int j = 0; j != 100; ++j)
     X[j+i*100] = 0;
}

into a single memset of 10000 bytes.  This series of changes
should also be helpful for other nested loop scenarios as well.

llvm-svn: 123079

llvm-svn: 123078

moving the OrigHeader block anymore: we just merge it away anyway so
its code layout doesn't matter.

llvm-svn: 123077

llvm-svn: 123076

that it was leaving in loops after rotation (between the original latch
block and the original header.

With this change, it is possible for rotated loops to have just a single
basic block, which is useful.

llvm-svn: 123075

loop info.

llvm-svn: 123074

llvm-svn: 123073

1. Rip out LoopRotate's domfrontier updating code.  It isn't
   needed now that LICM doesn't use DF and it is super complex
   and gross.
2. Make DomTree updating code a lot simpler and faster.  The 
   old loop over all the blocks was just to find a block??
3. Change the code that inserts the new preheader to just use
   SplitCriticalEdge instead of doing an overcomplex 
   reimplementation of it.

No behavior change, except for the name of the inserted preheader.

llvm-svn: 123072

llvm-svn: 123071

On Windows, replace each occurrence of '\' by '\\' on the replacement string. This is necessary to prevent re.sub from replacing escape sequences occurring in path.

For example:

llvm\tools\clang\test
was replaced by
llvm <tab> ools\clang <tab> est

llvm-svn: 123070

and latch blocks.  Reorder entry conditions to make hte pass faster
and more logical.

llvm-svn: 123069

llvm-svn: 123068

that are just passed to one function.

llvm-svn: 123067

to violate LCSSA form

llvm-svn: 123066

llvm-svn: 123065

they all ready do). This removes two dominator recomputations prior to isel,
which is a 1% improvement in total llc time for 403.gcc.

The only potentially suspect thing is making GCStrategy recompute dominators if
it used a custom lowering strategy.

llvm-svn: 123064

Add a unnamed_addr bit to global variables and functions. This will be used
to indicate that the address is not significant and therefore the constant
or function can be merged with others.

If an optimization pass can show that an address is not used, it can set this.

Examples of things that can have this set by the FE are globals created to
hold string literals and C++ constructors.

Adding unnamed_addr to a non-const global should have no effect unless
an optimization can transform that global into a constant.

Aliases are not allowed to have unnamed_addr since I couldn't figure
out any use for it.

llvm-svn: 123063

top of subloop headers, as the phi uses logically occur outside of the subloop.

llvm-svn: 123062

llvm-svn: 123061

them into the loop preheader, eliminating silly instructions like
"icmp i32 0, 100" in fixed tripcount loops.  This also better exposes the 
bigger problem with loop rotate that I'd like to fix: once this has been
folded, the duplicated conditional branch *often* turns into an uncond branch.

Not aggressively handling this is pessimizing later loop optimizations 
somethin' fierce by making "dominates all exit blocks" checks fail.

llvm-svn: 123060

llvm-svn: 123059

1. Take a flags argument instead of a bool.  This makes
   it more clear to the reader what it is used for.
2. Add a flag that says that "remapping a value not in the
   map is ok".
3. Reimplement MapValue to share a bunch of code and be a lot
   more efficient.  For lookup failures, don't drop null values
   into the map.
4. Using the new flag a bunch of code can vaporize in LinkModules
   and LoopUnswitch, kill it.

No functionality change.

llvm-svn: 123058

map from ValueMapper.h (giving us access to its utilities)
and add a fastpath in the loop rotation code, avoiding expensive
ssa updator manipulation for values with nothing to update.

llvm-svn: 123057

temporaries with no-return destructors. The CFG now properly supports
temporaries and implicit destructors which both makes this kludge no
longer work, and conveniently removes the need for it.

Turn on CFG handling of implicit destructors and initializers. Several
ad-hoc benchmarks don't indicate any measurable performance impact from
growing the CFG, and it fixes real correctness problems with warnings.

As a result of turning on these CFG elements, we started to tickle an
inf-loop in the unreachable code logic used for warnings. The fix is
trivial.

llvm-svn: 123056

prefix in a printf format string is matched
with the appropriate conversion specifier.

llvm-svn: 123055

prefix to format conversions (POSIX extension).

llvm-svn: 123054

new "hexname" key for the "key:value;" duple that is part of the packet. This
allows for thread names to contain special characters such as $ # : ; + -

Debugserver now detects if the thread name contains special characters and
sends the chars in hex format if needed.

llvm-svn: 123053

frames, UnwindLLDB could create the incorrect RegisterContext for a given
stack frame because it was using the frame index (not the concrete frame
index). This was causing crashes when doing backtraces through the 
SBFrame::GetFP() because a NULL register context was being returned for the
deepest stack frame.

llvm-svn: 123052

llvm-svn: 123051

llvm-svn: 123049

llvm-svn: 123048

was being searched and sorted using a shared pointer as the value which means
the pointer value was what was being searched for. This means that anytime
you did a stack backtrace, the collection of FuncUnwinders doubled and then
the array or shared pointer got sorted (by pointer value), so you had an ever
increasing collection of shared pointer where a match was never found. This
means we had a ton of duplicates in this table and would cause issues after
one had been debugging for a long time.

llvm-svn: 123045

Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.

llvm-svn: 123044

This was suggested by Edmund Grimley Evans in pr8411.

llvm-svn: 123043

llvm-svn: 123042

llvm-svn: 123041

llvm-svn: 123040

llvm-svn: 123039