for debugging and exception handling.

llvm-svn: 33550

llvm-svn: 33537

llvm-svn: 32698

is 'unsigned'.

llvm-svn: 32279

simplified before we do this xform so that our cost model is accurate.

llvm-svn: 31864

llvm-svn: 31861

This speeds up yacr2 by 7% on a core2.

llvm-svn: 31856

  if (cond) goto BB2
BB1:
    ...
    return;
BB2:
   ...

Move BB1 to the end of the function so that the code falls through in the
non-return case.  This has the effect of moving assert (and other no-return
call) bodies and return blocks out of loops.

llvm-svn: 31855

LBB1_57:        #bb207.i
        movl 72(%esp), %ecx
        movb (%ecx,%eax), %cl
        movl 80(%esp), %edx
        movb %cl, 1(%edx,%eax)
        incl %eax
        cmpl $143, %eax
        jne LBB1_57     #bb207.i
        jmp LBB1_64     #cond_next255.i

intead of:

LBB1_57:        #bb207.i
        movl 72(%esp), %ecx
        movb (%ecx,%eax), %cl
        movl 80(%esp), %edx
        movb %cl, 1(%edx,%eax)
        incl %eax
        cmpl $143, %eax
        je LBB1_64      #cond_next255.i
        jmp LBB1_57     #bb207.i

This eliminates a branch per iteration of the loop.  This hurted PPC
particularly, because the extra branch meant another dispatch group for each
iteration of the loop.

llvm-svn: 31530

llvm-svn: 31464

Turn on -Wunused and -Wno-unused-parameter. Clean up most of the resulting
fall out by removing unused variables. Remaining warnings have to do with
unused functions (I didn't want to delete code without review) and unused
variables in generated code. Maintainers should clean up the remaining
issues when they see them. All changes pass DejaGnu tests and Olden.

llvm-svn: 31380

it inserts an uncond branch where it is less likely to cause a problem.  This
fixes some perf issues on ppc.

llvm-svn: 31354

tail is not an entire block for either of them, pick one, split it, then
merge the common part.

llvm-svn: 31336

llvm-svn: 31335

successors), and make island block movement more general.

This compiles CodeGen/X86/2006-04-27-ISelFoldingBug.ll to:

_loadAndRLEsource_no_exit_2E_1_label_2E_0:
        subl $8, %esp
        movl %esi, 4(%esp)
        movl %ebx, (%esp)
        movl 16(%esp), %eax
        movl 12(%esp), %ecx
LBB1_3: #label.0
        movl _last, %edx
        movl %edx, %esi
        incl %esi
        movl %esi, _last
        movl %ecx, %ebx
        # TRUNCATE movb %bl, %bl
        movl _block, %esi
        movb %bl, 1(%esi,%edx)
        cmpl %eax, _last
        jge LBB1_2      #codeRepl5.exitStub
LBB1_4: #label.0
        cmpl $257, %ecx
        je LBB1_2       #codeRepl5.exitStub
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
        movl $1, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_2: #codeRepl5.exitStub
        xorl %eax, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret

instead of:

_loadAndRLEsource_no_exit_2E_1_label_2E_0:
        subl $8, %esp
        movl %esi, 4(%esp)
        movl %ebx, (%esp)
        movl 16(%esp), %eax
        movl 12(%esp), %ecx
        jmp LBB1_3      #label.0
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
        movl $1, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_2: #codeRepl5.exitStub
        xorl %eax, %eax
        movl (%esp), %ebx
        movl 4(%esp), %esi
        addl $8, %esp
        ret
LBB1_3: #label.0
        movl _last, %edx
        movl %edx, %esi
        incl %esi
        movl %esi, _last
        movl %ecx, %ebx
        # TRUNCATE movb %bl, %bl
        movl _block, %esi
        movb %bl, 1(%esi,%edx)
        cmpl %eax, _last
        jge LBB1_2      #codeRepl5.exitStub
LBB1_4: #label.0
        cmpl $257, %ecx
        jne LBB1_1      #label.0.no_exit.1_crit_edge.exitStub
        jmp LBB1_2      #codeRepl5.exitStub

... which is much better layout :)

llvm-svn: 31282

jump tables that are dead.

llvm-svn: 31273

the pred block doesn't fall through into them if it's a jumptable.

llvm-svn: 31263

llvm-svn: 31188

llvm-svn: 31180

a place more useful.  In particular, if we can put them in a place where code
will be able to fall into it, do so.  Otherwise, put it in a place it can fall
through into a successor.  Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.

This deletes several hundred unconditional branches from spass.

llvm-svn: 31149

llvm-svn: 31140

llvm-svn: 31129

llvm-svn: 31102

        call L_strcmp$stub
        testl %eax, %eax
-       jne LBB26_208   #cond_true6020
-       jmp LBB26_227   #bb7119
+       je LBB26_227    #bb7119
 LBB26_208:     #cond_true6020
        movl $l31_str14, 4(%esp)

        testl %eax, %eax
-       jne LBB26_704   #cond_true13042
-       jmp LBB26_713   #bb13151
+       je LBB26_713    #bb13151
 LBB26_704:     #cond_true13042
        movl $_str52, 4(%esp)

        cmpl 76(%ecx), %eax
-       jge LBB26_1628  #cond_false63.i.i
-       jmp LBB26_1769  #_Z8makeGridP13mrSurfaceListidiidd.exit.i
+       jl LBB26_1769   #_Z8makeGridP13mrSurfaceListidiidd.exit.i
 LBB26_1628:    #cond_false63.i.i
        movl $0, 48964(%esp)

llvm-svn: 31100

  jle FOO
  jmp BAR
BAR:

into:

  jle FOO
BAR:

... whoa!

llvm-svn: 31098

1. Remove a bunch of ifdef'd code.
2. When a block just contains an uncond branch, change all blocks branching
   to it to jump to the destination instead.
3. If branch analysis tells us some edges in the machinecfg are not actually
   possible, remove them.

#2 triggers a suprisingly large number of times.

llvm-svn: 31094

This is currently disabled by default and limited in several ways, but does
have a positive effect.

llvm-svn: 31090

# notes in it.

llvm-svn: 31026

branch folding can now compile stuff like this:

void foo(int W, int X, int Y, int Z) {
  if (W & 1) {
    for (; X;--X) bar();
  } else if (W & 2) {
    for (; Y;--Y) bar();
  } else if (W & 4) {
    for (; Z;--Z) bar();
  } else if (W & 8) {
    for (; W;--W) bar();
  }

  if (W) {
    bar();
  }
}

contrived testcase where loops exits all end up merging together.  To have
the loop merges be:

...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...

instead of:


...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
        b LBB1_20       ;cond_next48
LBB1_17:        ;cond_next48.loopexit1
        b LBB1_20       ;cond_next48
LBB1_18:        ;cond_next48.loopexit2
        b LBB1_20       ;cond_next48
LBB1_19:        ;cond_next48.loopexit3
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...


This is CodeGen/PowerPC/branch-opt.ll

llvm-svn: 31006

It now correctly deletes unreachable blocks and blocks that are empty.

llvm-svn: 31000

llvm-svn: 30951

llvm-svn: 30950

llvm-svn: 30939

llvm-svn: 21420

Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.

llvm-svn: 16137

llvm-svn: 15402

MachineBasicBlock* as a parameter so that nxext() and prior() helper
functions can work naturally on it.

llvm-svn: 15376

llvm-svn: 15375

MachineFunction::iterator instead of MachineBasicBlock* to avoid
dereferencing end iterators.

llvm-svn: 15373

FallThrough maybe == to MF.end().

llvm-svn: 15372