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

value.  This allows us to turn more globals into constants and eliminate them.
This patch implements GlobalOpt/load-store-global.llx.

Note that this patch speeds up 255.vortex from:

Output/255.vortex.out-cbe.time:program 7.640000
Output/255.vortex.out-llc.time:program 9.810000

to:

Output/255.vortex.out-cbe.time:program 7.250000
Output/255.vortex.out-llc.time:program 9.490000

Which isn't bad at all!

llvm-svn: 17746

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

llvm-svn: 17734

constant value.  This makes the return value dead and allows for
simplification in the caller.

This implements IPConstantProp/return-constant.ll

This triggers several dozen times throughout SPEC.

llvm-svn: 17730

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

llvm-svn: 17719

argument pointers.  This is only valid to do if the function already
unconditionally loaded an argument or if the pointer passed in is known
to be valid.  Make sure to do the required checks.

This fixed ArgumentPromotion/control-flow.ll and the Burg program.

llvm-svn: 17718

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: 17699

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

llvm-svn: 17697

llvm-svn: 17696

as IPCP opportunities.

llvm-svn: 17680

llvm-svn: 17679

This implements IPConstantProp/recursion.ll

llvm-svn: 17666

This allows to elimination of a bunch of global pool descriptor args from
programs being pool allocated (and is also generally useful!)

llvm-svn: 17657

nightly testers

llvm-svn: 17646

llvm-svn: 17642

exciting to inline.  Only inline medium or small sized functions with a
single call site.

llvm-svn: 17588

llvm-svn: 17545

llvm-svn: 17482

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

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

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: 17163

llvm-svn: 17161

llvm-svn: 17157

llvm-svn: 17155

llvm-svn: 17146