llvm-svn: 17821

 1. Speedup getValueState by having it not consider Arguments.  It's better
    to just add them before we start SCCP'ing.
 2. SCCP can delete the contents of dead blocks.  No really, it's ok!  This
    reduces the size of the IR for subsequent passes, even though
    simplifycfg would do the same job.  In practice, simplifycfg does not
    run until much later than sccp in gccas

llvm-svn: 17820

llvm-svn: 17818

class.  The only changes are minor:

 * Do not try to SCCP instructions that return void in the rewrite loop.
   This is silly and fool hardy, wasting a map lookup and adding an entry
   to the map which is never used.
 * If we decide something has an undefined value, rewrite it to undef,
   potentially leading to further simplications.

llvm-svn: 17816

If this happens, detect it early instead of relying on instcombine to notice
it later.  This can be a big speedup, because PHI nodes can have many
incoming values.

llvm-svn: 17741

This exposes subsequent optimization possiblities and reduces code size.
This triggers 1423 times in spec.

llvm-svn: 17740

  %X = alloca ...
  %Y = alloca ...
    X == Y

into false.  This allows us to simplify some stuff in eon (and probably
many other C++ programs) where operator= was checking for self assignment.
Folding this allows us to SROA several additional structs.

llvm-svn: 17735

of the array is just two.  This occurs 8 times in gcc, 6 times in crafty, and
12 times in 099.go.

This implements ScalarRepl/sroa_two.ll

llvm-svn: 17727

llvm-svn: 17724

for (X * C1) + (X * C2) (where * can be mul or shl), allowing us to fold:

   Y+Y+Y+Y+Y+Y+Y+Y

into
         %tmp.8 = shl long %Y, ubyte 3           ; <long> [#uses=1]

instead of

        %tmp.4 = shl long %Y, ubyte 2           ; <long> [#uses=1]
        %tmp.12 = shl long %Y, ubyte 2          ; <long> [#uses=1]
        %tmp.8 = add long %tmp.4, %tmp.12               ; <long> [#uses=1]

This implements add.ll:test25

Also add support for (X*C1)-(X*C2) -> X*(C1-C2), implementing sub.ll:test18

llvm-svn: 17704

   (X + (X << C2)) --> X * ((1 << C2) + 1)
   ((X << C2) + X) --> X * ((1 << C2) + 1)

This means that we now canonicalize "Y+Y+Y" into:

        %tmp.2 = mul long %Y, 3         ; <long> [#uses=1]

instead of:

        %tmp.10 = shl long %Y, ubyte 1          ; <long> [#uses=1]
        %tmp.6 = add long %Y, %tmp.10               ; <long> [#uses=1]

llvm-svn: 17701

will actually get it.

llvm-svn: 17700

llvm-svn: 17696

llvm-svn: 17545

llvm-svn: 17481

* Disable broken transforms for simplifying (setcc (cast X to larger), CI)
  where CC is not != or ==

llvm-svn: 17422

#define CL0(a) case a: f(); 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 comes from GCC PR 15524

llvm-svn: 17390

llvm-svn: 17286

and work better with VC++.  Patch contributed by Morten Ofstad!

llvm-svn: 17281

http://mail.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20041018/019708.html

exposed ANOTHER latent bug in this xform, which caused Prolangs-C/bison to fill
the zion nightly tester disk up and make the tester barf.

This is obviously not a good thing, so lets fix this bug shall we? :)

llvm-svn: 17276

llvm-svn: 17270

llvm-svn: 17218

llvm-svn: 17157

llvm-svn: 17155

doing... I guess they're right.

llvm-svn: 17142

llvm-svn: 17136

loops.  This optimization is not turned on by default yet, but may be run
with the opt tool's -loop-reduce flag.  There are many FIXMEs listed in the
code that will make it far more applicable to a wide range of code, but you
have to start somewhere :)

This limited version currently triggers on the following tests in the
MultiSource directory:
pcompress2: 7 times
cfrac: 5 times
anagram: 2 times
ks: 6 times
yacr2: 2 times

llvm-svn: 17134

Patch contributed by Morten Ofstad. Thanks Morten!

llvm-svn: 17123

change hacks off 10K of bytecode from perlbmk (.5%) even though the front-end
is not generating them yet and we are not optimizing the resultant code.
This isn't too bad.

llvm-svn: 17111

llvm-svn: 17110

occurs in the entry node of a function

llvm-svn: 17109

exercise that I'm not interested in tackling right now.  Just punt and treat them
like unwind's.

This 'fixes' test/Regression/Transforms/ADCE/unreachable-function.ll

llvm-svn: 17106

other blocks.

llvm-svn: 17099

so prepare for this.

llvm-svn: 17095

llvm-svn: 17069

llvm-svn: 17067

ugly and giant constnat exprs in some programs.

llvm-svn: 17066

llvm-svn: 17047

ignore unreachable instructions

llvm-svn: 17044

llvm-svn: 17043