llvm-svn: 21427

llvm-svn: 21393

convert this:

        %tmp.1 = seteq int %i, 0                ; <bool> [#uses=1]
        br bool %tmp.1, label %shortcirc_done, label %shortcirc_next

shortcirc_next:         ; preds = %entry
        %tmp.4 = seteq int %j, 0                ; <bool> [#uses=1]
        br label %shortcirc_done

shortcirc_done:         ; preds = %shortcirc_next, %entry
        %shortcirc_val = phi bool [ %tmp.4, %shortcirc_next ], [ true, %entry ]         ; <bool> [#uses=1]

to this:
        %tmp.1 = seteq int %i, 0                ; <bool> [#uses=1]
        %tmp.4 = seteq int %j, 0                ; <bool> [#uses=1]
        %shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4             ; <bool> [#uses=1]

... which is later simplified by instcombine into an or.

llvm-svn: 21388

llvm-svn: 21253

Bill Wendling!!

llvm-svn: 20649

using Function::arg_{iterator|begin|end}.  Likewise Module::g* -> Module::global_*.

This patch is contributed by Gabor Greif, thanks!

llvm-svn: 20597

llvm-svn: 20463

llvm-svn: 20343

llvm-svn: 20334

This does a simple form of "jump threading", which eliminates CFG edges that
are provably dead.  This triggers 90 times in the external tests, and
eliminating CFG edges is always always a good thing! :)

llvm-svn: 20300

llvm-svn: 19898

SimplifyCFG is one of those passes that we use for final cleanup: it should
not rely on other passes to clean up its garbage.  This fixes the "why are
trivially dead setcc's in the output of gccas" problem.

llvm-svn: 19212

llvm-svn: 18799

and the failure on make_dparser last night.

llvm-svn: 18766

llvm-svn: 18381

This only fails on darwin or on X86 under valgrind.

llvm-svn: 18377

llvm-svn: 18369

  if (x) {
    code
    ...
  } else {
    code
    ...
  }

Turn it into:

  code
  if (x) {
    ...
  } else {
    ...
  }

This reduces code size and in some common cases allows us to completely
eliminate the conditional.  This turns several if/then/else blocks in loops
into straightline code in 179.art, turning the loops into single basic blocks
(good for modsched even!).

Maybe now brg will leave me alone ;-)

llvm-svn: 18366

llvm-svn: 18028

llvm-svn: 17699

instructions, setting DefBlock to a block it did not have dom info for.

llvm-svn: 17697

This speeds up simplifycfg on this program, from 44.87s to 0.29s (with
a profiled build):

 #define CL0(a) case a: goto c;
 #define CL1(a) CL0(a##0) CL0(a##1) CL0(a##2) CL0(a##3) CL0(a##4) CL0(a##5) \
 CL0(a##6) CL0(a##7) CL0(a##8) CL0(a##9)
 #define CL2(a) CL1(a##0) CL1(a##1) CL1(a##2) CL1(a##3) CL1(a##4) CL1(a##5) \
 CL1(a##6) CL1(a##7) CL1(a##8) CL1(a##9)
 #define CL3(a) CL2(a##0) CL2(a##1) CL2(a##2) CL2(a##3) CL2(a##4) CL2(a##5) \
 CL2(a##6) CL2(a##7) CL2(a##8) CL2(a##9)
 #define CL4(a) CL3(a##0) CL3(a##1) CL3(a##2) CL3(a##3) CL3(a##4) CL3(a##5) \
 CL3(a##6) CL3(a##7) CL3(a##8) CL3(a##9)

 void f();

 void a() {
     int b;
  c: switch (b) {
         CL4(1)
     }
 }

This testcase is contrived to expose N^2 behavior, but this patch should speedup
simplifycfg on any programs that use large switch statements.  This testcase
comes from GCC PR17895.

llvm-svn: 17389

llvm-svn: 17286

llvm-svn: 17163

llvm-svn: 17155

llvm-svn: 17136

Patch contributed by Morten Ofstad. Thanks Morten!

llvm-svn: 17123

Simplify code by simplifying terminators that branch to blocks that start
with an unreachable instruction.

llvm-svn: 17116

particular, invoke ret values are only live in the normal dest of the invoke
not in the unwind dest.

llvm-svn: 17108

If a function had no return instruction in it, and the result of the inlined
call instruction was used, we would crash.

llvm-svn: 17104

unneccesary.  This allows us to delete several hundred phi nodes of the
form PHI(x,x,x,undef) from 253.perlbmk and probably other programs as well.

This implements Mem2Reg/UndefValuesMerge.ll

llvm-svn: 17098

to think that PHI[4, undef] == 4.

llvm-svn: 17096

llvm-svn: 17056

llvm-svn: 17046

llvm-svn: 17045

nodes unless we KNOW that we are able to promote all of them.

This fixes: test/Regression/Transforms/SimplifyCFG/PhiNoEliminate.ll

llvm-svn: 16973

llvm-svn: 16950

llvm-svn: 16893

potentially fold more in one pass.

llvm-svn: 16583

whose addresses where used by trivial phi nodes and select instructions.  This
is now performed by the instcombine pass, which is more powerful, is much
simpler, and is faster.  This allows the deletion of a bunch of code, two
FIXME's and two gotos.

llvm-svn: 16406