llvm-svn: 17110

occurs in the entry node of a function

llvm-svn: 17109

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

llvm-svn: 17108

where C requires semicolons in some cases to indicate null statements.

llvm-svn: 17107

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

llvm-svn: 17105

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

llvm-svn: 17103

Pass -single_module option to gcc when linking dynamic libraries for use with bugpoint, so that we can bugpoint multiple .cp files

llvm-svn: 17102

llvm-svn: 17101

This comes up many times in perlbmk and probably others.

llvm-svn: 17100

other blocks.

llvm-svn: 17099

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

llvm-svn: 17097

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

llvm-svn: 17096

so prepare for this.

llvm-svn: 17095

0->field, which is illegal.  Now we print ((foo*)0)->field.

The second hunk is an optimization to not print undefined phi values.

llvm-svn: 17094

last night. :)  bork!

llvm-svn: 17093

llvm-svn: 17092

llvm-svn: 17091

llvm-svn: 17090

llvm-svn: 17089

llvm-svn: 17088

llvm-svn: 17087

llvm-svn: 17086

llvm-svn: 17085

llvm-svn: 17084

double %test(uint %X) {
        %tmp.1 = cast uint %X to double         ; <double> [#uses=1]
        ret double %tmp.1
}

into:

test:
        sub %ESP, 8
        mov %EAX, DWORD PTR [%ESP + 12]
        mov %ECX, 0
        mov DWORD PTR [%ESP], %EAX
        mov DWORD PTR [%ESP + 4], %ECX
        fild QWORD PTR [%ESP]
        add %ESP, 8
        ret

... which basically zero extends to 8 bytes, then does an fild for an
8-byte signed int.

Now we generate this:


test:
        sub %ESP, 4
        mov %EAX, DWORD PTR [%ESP + 8]
        mov DWORD PTR [%ESP], %EAX
        fild DWORD PTR [%ESP]
        shr %EAX, 31
        fadd DWORD PTR [.CPItest_0 + 4*%EAX]
        add %ESP, 4
        ret

        .section .rodata
        .align  4
.CPItest_0:
        .quad   5728578726015270912

This does a 32-bit signed integer load, then adds in an offset if the sign
bit of the integer was set.

It turns out that this is substantially faster than the preceeding sequence.
Consider this testcase:

unsigned a[2]={1,2};
volatile double G;

void main() {
    int i;
    for (i=0; i<100000000; ++i )
        G += a[i&1];
}

On zion (a P4 Xeon, 3Ghz), this patch speeds up the testcase from 2.140s
to 0.94s.

On apoc, an athlon MP 2100+, this patch speeds up the testcase from 1.72s
to 1.34s.

Note that the program takes 2.5s/1.97s on zion/apoc with GCC 3.3 -O3
-fomit-frame-pointer.

llvm-svn: 17083

us to use index registers for CPI's

llvm-svn: 17082

index reg and scale

llvm-svn: 17081

  %X = and Y, constantint
  %Z = setcc %X, 0

instead of emitting:

        and %EAX, 3
        test %EAX, %EAX
        je .LBBfoo2_2   # UnifiedReturnBlock

We now emit:

        test %EAX, 3
        je .LBBfoo2_2   # UnifiedReturnBlock

This triggers 581 times on 176.gcc for example.

llvm-svn: 17080

llvm-svn: 17079

1. optional shift left
2. and x, immX
3. and y, immY
4. or z, x, y
==> rlwimi z, x, y, shift, mask begin, mask end

where immX == ~immY and immX is a run of set bits. This transformation
fires 32 times on voronoi, once on espresso, and probably several
dozen times on external benchmarks such as gcc.

To put this in terms of actual code generated for
struct B { unsigned a : 3; unsigned b : 2; };
void storeA (struct B *b, int v) { b->a = v;}
void storeB (struct B *b, int v) { b->b = v;}

Old:
_storeA:
        rlwinm r2, r4, 0, 29, 31
        lwz r4, 0(r3)
        rlwinm r4, r4, 0, 0, 28
        or r2, r4, r2
        stw r2, 0(r3)
        blr

_storeB:
        rlwinm r2, r4, 3, 0, 28
        rlwinm r2, r2, 0, 27, 28
        lwz r4, 0(r3)
        rlwinm r4, r4, 0, 29, 26
        or r2, r2, r4
        stw r2, 0(r3)
        blr

New:
_storeA:
        lwz r2, 0(r3)
        rlwimi r2, r4, 0, 29, 31
        stw r2, 0(r3)
        blr

_storeB:
        lwz r2, 0(r3)
        rlwimi r2, r4, 3, 27, 28
        stw r2, 0(r3)
        blr

llvm-svn: 17078

llvm-svn: 17077

llvm-svn: 17076

for undef.

llvm-svn: 17075

llvm-svn: 17074

llvm-svn: 17073

llvm-svn: 17072

that we undefine the macro before using its name in the definition. This
can happen on Linux if _GNU_SOURCE is defined.

llvm-svn: 17071