Use this information to avoid doing expensive interval intersections for
registers that could not possible be interesting.  This speeds up linscan
on ia64 compiling kc++ in release mode from taking 7.82s to 4.8s(!), total
itanium llc time on this program is 27.3s now.  This marginally speeds up
PPC and X86, but they appear to be limited by other parts of linscan, not
this code.

On this program, on itanium, live intervals now takes 41% of llc time.

llvm-svn: 22986

llvm-svn: 22985

x%y for 'rem' on fp values.

llvm-svn: 22984

llvm-svn: 22983

llvm-svn: 22982

llvm-svn: 22981

llvm-svn: 22979

either seteq X, 0 or srl (ctlz X), size(X-1), depending on what's legal
for the target.

llvm-svn: 22978

llvm-svn: 22977

llvm-svn: 22976

llvm-svn: 22975

in the asmprinter.  This changes the .td files to use lower case register names,
avoiding the need to do this call.  This speeds up the asmprinter from 1.52s
to 1.06s on kc++ in a release build.

llvm-svn: 22974

It used to crash on any function that took float arguments.

llvm-svn: 22973

number of regs (e.g. most riscs), many functions won't need to use callee
clobbered registers.  Do a speculative check to see if we can get a free
register without processing the fixed list (which has all of these).  This
saves a lot of time on machines with lots of callee clobbered regs (e.g.
ppc and itanium, also x86).

This reduces ppc llc compile time from 184s -> 172s on kc++.  This is probably
worth FAR FAR more on itanium though.

llvm-svn: 22972

we spill out of the fast path.  The scan of active_ and the calls to
updateSpillWeights don't need to happen unless a spill occurs.  This reduces
debug llc time of kc++ with ppc from 187.3s to 183.2s.

llvm-svn: 22971

llvm-svn: 22970

promoted to the right type.  This fixes: IA64/2005-08-22-LegalizerCrash.ll

llvm-svn: 22969

llvm-svn: 22968

llvm-svn: 22967

add some comments.  This loop really needs to be reevaluated!

llvm-svn: 22966

llvm-svn: 22965

llvm-svn: 22964

llvm-svn: 22963

allowing us to compile this:

float %test2(float* %P) {
        %Q = load float* %P
        %R = add float %Q, 10.1
        ret float %R
}

to this:

_test2:
        lfs r2, 0(r3)
        lis r3, ha16(.CPI_test2_0)
        lfs r3, lo16(.CPI_test2_0)(r3)
        fadds f1, r2, r3
        blr

llvm-svn: 22962

float %test2(float* %P) {
        %Q = load float* %P
        %R = add float %Q, %Q
        ret float %R
}

By returning the right result.

llvm-svn: 22961

Make sure expressions only have one use before emitting them into a place that is conditionally executed

llvm-svn: 22960

llvm-svn: 22959

llvm-svn: 22958

llvm-svn: 22957

llvm-svn: 22956

llvm-svn: 22955

llvm-svn: 22954

llvm-svn: 22953

simplifies BRTWOWAY into BR if one of the results is a fall-through.
Unless I'm missing something, there is no reason to duplicate this
in the target-specific code.

llvm-svn: 22952

llvm-svn: 22951

llvm-svn: 22950

llvm-svn: 22949

llvm-svn: 22948

the old condition to a one bit value.  The incoming value must have been
promoted, and the top bits are undefined.  This causes us to generate:

_test:
        rlwinm r2, r3, 0, 31, 31
        li r3, 17
        cmpwi cr0, r2, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        li r3, 1
.LBB_test_2:    ;
        blr

instead of:

_test:
        rlwinm r2, r3, 0, 31, 31
        li r2, 17
        cmpwi cr0, r3, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        li r2, 1
.LBB_test_2:    ;
        or r3, r2, r2
        blr

for:

int %test(bool %c) {
        %retval = select bool %c, int 17, int 1
        ret int %retval
}

llvm-svn: 22947

it in the block.  This codegens:

int %test(bool %c) {
        %retval = select bool %c, int 17, int 1
        ret int %retval
}

as:

_test:
        rlwinm r2, r3, 0, 31, 31
        li r2, 17
        cmpwi cr0, r3, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        li r2, 1
.LBB_test_2:    ;
        or r3, r2, r2
        blr

instead of:

_test:
        rlwinm r2, r3, 0, 31, 31
        li r2, 17
        li r4, 1
        cmpwi cr0, r3, 0
        bne .LBB_test_2 ;
.LBB_test_1:    ;
        or r2, r4, r4
.LBB_test_2:    ;
        or r3, r2, r2
        blr

... which is one fewer instruction.  The savings are more significant for
global address and constantfp nodes.

llvm-svn: 22946