Commit Graph

140 Commits

Author SHA1 Message Date
Andrew Lenharth
50a0d426e8 This should be a win of every arch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27364 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-02 21:42:45 +00:00
Chris Lattner
350bec0fb9 Add a little dag combine to compile this:
int %AreSecondAndThirdElementsBothNegative(<4 x float>* %in) {
entry:
        %tmp1 = load <4 x float>* %in           ; <<4 x float>> [#uses=1]
        %tmp = tail call int %llvm.ppc.altivec.vcmpgefp.p( int 1, <4 x float> < float 0x7FF8000000000000, float 0.000000e+00, float 0.000000e+00, float 0x7FF8000000000000 >, <4 x float> %tmp1 )           ; <int> [#uses=1]
        %tmp = seteq int %tmp, 0                ; <bool> [#uses=1]
        %tmp3 = cast bool %tmp to int           ; <int> [#uses=1]
        ret int %tmp3
}

into this:

_AreSecondAndThirdElementsBothNegative:
        mfspr r2, 256
        oris r4, r2, 49152
        mtspr 256, r4
        li r4, lo16(LCPI1_0)
        lis r5, ha16(LCPI1_0)
        lvx v0, 0, r3
        lvx v1, r5, r4
        vcmpgefp. v0, v1, v0
        mfcr r3, 2
        rlwinm r3, r3, 27, 31, 31
        mtspr 256, r2
        blr

instead of this:

_AreSecondAndThirdElementsBothNegative:
        mfspr r2, 256
        oris r4, r2, 49152
        mtspr 256, r4
        li r4, lo16(LCPI1_0)
        lis r5, ha16(LCPI1_0)
        lvx v0, 0, r3
        lvx v1, r5, r4
        vcmpgefp. v0, v1, v0
        mfcr r3, 2
        rlwinm r3, r3, 27, 31, 31
        xori r3, r3, 1
        cntlzw r3, r3
        srwi r3, r3, 5
        mtspr 256, r2
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27356 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-02 06:11:11 +00:00
Chris Lattner
edab1b9133 Constant fold all of the vector binops. This allows us to compile this:
"vector unsigned char mergeLowHigh = (vector unsigned char)
( 8, 9, 10, 11, 16, 17, 18, 19, 12, 13, 14, 15, 20, 21, 22, 23 );
vector unsigned char mergeHighLow = vec_xor( mergeLowHigh, vec_splat_u8(8));"

aka:

void %test2(<16 x sbyte>* %P) {
  store <16 x sbyte> cast (<4 x int> xor (<4 x int> cast (<16 x ubyte> < ubyte 8, ubyte 9, ubyte 10, ubyte 11, ubyte 16, ubyte 17, ubyte 18, ubyte 19, ubyte 12, ubyte 13, ubyte 14, ubyte 15, ubyte 20, ubyte 21, ubyte 22, ubyte 23 > to <4 x int>), <4 x int> cast (<16 x sbyte> < sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8, sbyte 8 > to <4 x int>)) to <16 x sbyte>), <16 x sbyte> * %P
  ret void
}

into this:

_test2:
        mfspr r2, 256
        oris r4, r2, 32768
        mtspr 256, r4
        li r4, lo16(LCPI2_0)
        lis r5, ha16(LCPI2_0)
        lvx v0, r5, r4
        stvx v0, 0, r3
        mtspr 256, r2
        blr

instead of this:

_test2:
        mfspr r2, 256
        oris r4, r2, 49152
        mtspr 256, r4
        li r4, lo16(LCPI2_0)
        lis r5, ha16(LCPI2_0)
        vspltisb v0, 8
        lvx v1, r5, r4
        vxor v0, v1, v0
        stvx v0, 0, r3
        mtspr 256, r2
        blr

... which occurs here:
http://developer.apple.com/hardware/ve/calcspeed.html


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27343 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-02 03:25:57 +00:00
Chris Lattner
6258fb2592 Implement constant folding of bit_convert of arbitrary constant vbuild_vector nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27341 91177308-0d34-0410-b5e6-96231b3b80d8
2006-04-02 02:53:43 +00:00
Chris Lattner
f1d0c623c6 Delete identity shuffles, implementing CodeGen/Generic/vector-identity-shuffle.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27317 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-31 22:16:43 +00:00
Chris Lattner
29cd7db310 Remove dead *extloads. This allows us to codegen vector.ll:test_extract_elt
to:

test_extract_elt:
        alloc r3 = ar.pfs,0,1,0,0
        adds r8 = 12, r32
        ;;
        ldfs f8 = [r8]
        mov ar.pfs = r3
        br.ret.sptk.many rp

instead of:

test_extract_elt:
        alloc r3 = ar.pfs,0,1,0,0
        adds r8 = 28, r32
        adds r9 = 24, r32
        adds r10 = 20, r32
        adds r11 = 16, r32
        ;;
        ldfs f6 = [r8]
        ;;
        ldfs f6 = [r9]
        adds r8 = 12, r32
        adds r9 = 8, r32
        adds r14 = 4, r32
        ;;
        ldfs f6 = [r10]
        ;;
        ldfs f6 = [r11]
        ldfs f8 = [r8]
        ;;
        ldfs f6 = [r9]
        ;;
        ldfs f6 = [r14]
        ;;
        ldfs f6 = [r32]
        mov ar.pfs = r3
        br.ret.sptk.many rp


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27297 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-31 18:10:41 +00:00
Chris Lattner
e4b953939c Delete dead loads in the dag. This allows us to compile
vector.ll:test_extract_elt2 into:

_test_extract_elt2:
        lfd f1, 32(r3)
        blr

instead of:

_test_extract_elt2:
        lfd f0, 56(r3)
        lfd f0, 48(r3)
        lfd f0, 40(r3)
        lfd f1, 32(r3)
        lfd f0, 24(r3)
        lfd f0, 16(r3)
        lfd f0, 8(r3)
        lfd f0, 0(r3)
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27296 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-31 18:06:18 +00:00
Chris Lattner
cef896e50c When building a VVECTOR_SHUFFLE node from extract_element operations, make
sure to build it as SHUFFLE(X, undef, mask), not SHUFFLE(X, X, mask).

The later is not canonical form, and prevents the PPC splat pattern from
matching.  For a particular splat, we go from generating this:

	li r10, lo16(LCPI1_0)
	lis r11, ha16(LCPI1_0)
	lvx v3, r11, r10
	vperm v3, v2, v2, v3

to generating:

	vspltw v3, v2, 3


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27236 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-28 22:19:47 +00:00
Chris Lattner
66445d3e0a Canonicalize VECTOR_SHUFFLE(X, X, Y) -> VECTOR_SHUFFLE(X,undef,Y')
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27235 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-28 22:11:53 +00:00
Chris Lattner
d7648c8934 Turn a series of extract_element's feeding a build_vector into a
vector_shuffle node.  For this:

void test(__m128 *res, __m128 *A, __m128 *B) {
  *res = _mm_unpacklo_ps(*A, *B);
}

we now produce this code:

_test:
        movl 8(%esp), %eax
        movaps (%eax), %xmm0
        movl 12(%esp), %eax
        unpcklps (%eax), %xmm0
        movl 4(%esp), %eax
        movaps %xmm0, (%eax)
        ret

instead of this:

_test:
        subl $76, %esp
        movl 88(%esp), %eax
        movaps (%eax), %xmm0
        movaps %xmm0, (%esp)
        movaps %xmm0, 32(%esp)
        movss 4(%esp), %xmm0
        movss 32(%esp), %xmm1
        unpcklps %xmm0, %xmm1
        movl 84(%esp), %eax
        movaps (%eax), %xmm0
        movaps %xmm0, 16(%esp)
        movaps %xmm0, 48(%esp)
        movss 20(%esp), %xmm0
        movss 48(%esp), %xmm2
        unpcklps %xmm0, %xmm2
        unpcklps %xmm1, %xmm2
        movl 80(%esp), %eax
        movaps %xmm2, (%eax)
        addl $76, %esp
        ret

GCC produces this (with -fomit-frame-pointer):

_test:
        subl    $12, %esp
        movl    20(%esp), %eax
        movaps  (%eax), %xmm0
        movl    24(%esp), %eax
        unpcklps        (%eax), %xmm0
        movl    16(%esp), %eax
        movaps  %xmm0, (%eax)
        addl    $12, %esp
        ret


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27233 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-28 20:28:38 +00:00
Chris Lattner
4fbdd59f4f Don't crash on X^X if X is a vector. Instead, produce a vector of zeros.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27229 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-28 19:11:05 +00:00
Chris Lattner
6ea2dee6f6 Don't call SimplifyDemandedBits on vectors
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27128 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-25 22:19:00 +00:00
Chris Lattner
ca24244234 fold insertelement(buildvector) -> buildvector if the inserted element # is
a constant.  This implements test_constant_insert in CodeGen/Generic/vector.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26851 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-19 01:27:56 +00:00
Nate Begeman
81e8097377 Remove BRTWOWAY*
Make the PPC backend not dependent on BRTWOWAY_CC and make the branch
selector smarter about the code it generates, fixing a case in the
readme.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26814 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-17 01:40:33 +00:00
Chris Lattner
ac0f8f2929 make sure dead token factor nodes are removed by the dag combiner.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26731 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-13 18:37:30 +00:00
Chris Lattner
947c28935d Fold X+Y -> X|Y when safe. This implements:
Regression/CodeGen/PowerPC/and_add.ll

a case that occurs with dynamic allocas of constant size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26727 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-13 06:51:27 +00:00
Chris Lattner
79dbea5ab4 add a couple of missing folds
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26724 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-13 06:26:26 +00:00
Chris Lattner
cac7059d0f Reinstate this now that the offending opposite xform has been removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26548 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-05 19:53:55 +00:00
Evan Cheng
9176b0169c Back out fold (shl (add x, c1), c2) -> (add (shl x, c2), c1<<c2) for now.
It's causing an infinite loop compiling ldecod on x86 / Darwin.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26544 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-05 07:30:16 +00:00
Chris Lattner
12d830346b Add some simple copysign folds
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26543 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-05 05:30:57 +00:00
Chris Lattner
a1deca3cd6 fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
fold (shl (add x, c1), c2) -> (add (shl x, c2), c1<<c2)

This allows us to compile CodeGen/PowerPC/addi-reassoc.ll into:

_test1:
        slwi r2, r4, 4
        add r2, r2, r3
        lwz r3, 36(r2)
        blr
_test2:
        mulli r2, r4, 5
        add r2, r2, r3
        lbz r2, 11(r2)
        extsb r3, r2
        blr

instead of:

_test1:
        addi r2, r4, 2
        slwi r2, r2, 4
        add r2, r3, r2
        lwz r3, 4(r2)
        blr
_test2:
        addi r2, r4, 2
        mulli r2, r2, 5
        add r2, r3, r2
        lbz r2, 1(r2)
        extsb r3, r2
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26535 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-04 23:33:26 +00:00
Chris Lattner
1ec05d1bb4 Fix CodeGen/Generic/2006-03-01-dagcombineinfloop.ll, an infinite loop
in the dag combiner on 176.gcc on x86.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26459 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 21:47:21 +00:00
Chris Lattner
b2742f4a26 Fix a typo evan noticed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26454 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 19:55:35 +00:00
Chris Lattner
2466472a2b Add support for target-specific dag combines
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26443 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 04:53:38 +00:00
Chris Lattner
5750df9d69 Add a new AddToWorkList method, start using it
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26441 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 04:03:14 +00:00
Chris Lattner
0b1a85f110 Pull shifts by a constant through multiplies (a form of reassociation),
implementing Regression/CodeGen/X86/mul-shift-reassoc.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26440 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 03:44:24 +00:00
Evan Cheng
860771d2d8 Vector ops lowering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26436 91177308-0d34-0410-b5e6-96231b3b80d8
2006-03-01 01:09:54 +00:00
Chris Lattner
35a9f5a241 Compile:
unsigned foo4(unsigned short *P) { return *P & 255; }
unsigned foo5(short *P) { return *P & 255; }

to:

_foo4:
        lbz r3,1(r3)
        blr
_foo5:
        lbz r3,1(r3)
        blr

not:

_foo4:
        lhz r2, 0(r3)
        rlwinm r3, r2, 0, 24, 31
        blr
_foo5:
        lhz r2, 0(r3)
        rlwinm r3, r2, 0, 24, 31
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26419 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-28 06:49:37 +00:00
Chris Lattner
15045b6973 Fold "and (LOAD P), 255" -> zextload. This allows us to compile:
unsigned foo3(unsigned *P) { return *P & 255; }
as:
_foo3:
        lbz r3, 3(r3)
        blr

instead of:

_foo3:
        lwz r2, 0(r3)
        rlwinm r3, r2, 0, 24, 31
        blr

and:

unsigned short foo2(float a) { return a; }

as:
_foo2:
        fctiwz f0, f1
        stfd f0, -8(r1)
        lhz r3, -2(r1)
        blr

instead of:

_foo2:
        fctiwz f0, f1
        stfd f0, -8(r1)
        lwz r2, -4(r1)
        rlwinm r3, r2, 0, 16, 31
        blr


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26417 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-28 06:35:35 +00:00
Chris Lattner
71d9ebcbc1 fold (sra (sra x, c1), c2) -> (sra x, c1+c2)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26416 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-28 06:23:04 +00:00
Chris Lattner
2d2536c9d7 remove some completed notes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26390 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-27 00:39:31 +00:00
Chris Lattner
7d20d39009 Fix a problem Nate and Duraid reported where simplifying nodes can cause
them to get ressurected, in which case, deleting the undead nodes is
unfriendly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26291 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-20 06:51:04 +00:00
Nate Begeman
b0d04a7dea Add checks to make sure we don't create bogus extend nodes, and fix a bug
where we were doing exactly that which was causing failures on x86 and
alpha.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26284 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 02:40:58 +00:00
Chris Lattner
012f241987 Fix a tricky issue in the SimplifyDemandedBits code where CombineTo wasn't
exactly the API we wanted to call into.  This fixes the crash on crafty last
night.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26269 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 21:58:01 +00:00
Nate Begeman
fb7217bea3 Clean up DemandedBitsAreZero interface
Make more use of the new mask helpers in valuetypes.h
Combine (sra (srl x, c1), c1) -> sext_inreg if legal


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26263 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 19:54:08 +00:00
Nate Begeman
cd6a6ed0a9 Don't expand sdiv by power of two before legalize, since it will likely
generate illegal nodes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26261 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 07:26:20 +00:00
Nate Begeman
551bf3f800 kill ADD_PARTS & SUB_PARTS and replace them with fancy new ADDC, ADDE, SUBC
and SUBE nodes that actually expose what's going on and allow for
significant simplifications in the targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26255 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 05:43:56 +00:00
Nate Begeman
368e18d56a Rework the SelectionDAG-based implementations of SimplifyDemandedBits
and ComputeMaskedBits to match the new improved versions in instcombine.
Tested against all of multisource/benchmarks on ppc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26238 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-16 21:11:51 +00:00
Chris Lattner
8f4880be66 Lowering of sdiv X, pow2 was broken, this fixes it. This patch is written
by Nate, I'm just committing it for him.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26230 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-16 08:02:36 +00:00
Jim Laskey
d0e58e36a9 Should not combine ISD::LOCATIONs until we have scheme to remove from
MachineDebugInfo tables.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26216 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 19:34:44 +00:00
Chris Lattner
3391bcd434 Compile this:
xori r6, r2, 1
        rlwinm r6, r6, 0, 31, 31
        cmpwi cr0, r6, 0
        bne cr0, LBB1_3 ; endif

to this:

        rlwinm r6, r2, 0, 31, 31
        cmpwi cr0, r6, 0
        beq cr0, LBB1_3 ; endif


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26047 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-08 02:13:15 +00:00
Nate Begeman
be71442292 Back out previous commit, it isn't safe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26006 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-05 08:23:00 +00:00
Nate Begeman
bab9239d05 fold c1 << (x + c2) into (c1 << c2) << x. fix a warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26005 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-05 08:07:24 +00:00
Nate Begeman
c031e33b68 Handle urem by shifted powers of 2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26001 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-05 07:36:48 +00:00
Nate Begeman
fb5e4bdded handle combining A / (B << N) into A >>u (log2(B)+N) when B is a power of 2
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26000 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-05 07:20:23 +00:00
Nate Begeman
de99629e2a Add a framework for eliminating instructions that produces undemanded bits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25945 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 22:24:05 +00:00
Nate Begeman
cd4d58cef1 Add common code for reassociating ops in the dag combiner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25934 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-03 06:46:56 +00:00
Chris Lattner
3603cd62ae Turn any_extend nodes into zero_extend nodes when it allows us to remove an
and instruction.  This allows us to compile stuff like this:

bool %X(int %X) {
        %Y = add int %X, 14
        %Z = setne int %Y, 12345
        ret bool %Z
}

to this:

_X:
        cmpl $12331, 4(%esp)
        setne %al
        movzbl %al, %eax
        ret

instead of this:

_X:
        cmpl $12331, 4(%esp)
        setne %al
        movzbl %al, %eax
        andl $1, %eax
        ret

This occurs quite a bit with the X86 backend.  For example, 25 times in
lambda, 30 times in 177.mesa, 14 times in galgel,  70 times in fma3d,
25 times in vpr, several hundred times in gcc, ~45 times in crafty,
~60 times in parser, ~140 times in eon, 110 times in perlbmk, 55 on gap,
16 times on bzip2, 14 times on twolf, and 1-2 times in many other SPEC2K
programs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25901 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-02 07:17:31 +00:00
Chris Lattner
b3ddfc42af add two dag combines:
(C1-X) == C2 --> X == C1-C2
(X+C1) == C2 --> X == C2-C1

This allows us to compile this:

bool %X(int %X) {
        %Y = add int %X, 14
        %Z = setne int %Y, 12345
        ret bool %Z
}

into this:

_X:
        cmpl $12331, 4(%esp)
        setne %al
        movzbl %al, %eax
        andl $1, %eax
        ret

not this:

_X:
        movl $14, %eax
        addl 4(%esp), %eax
        cmpl $12345, %eax
        setne %al
        movzbl %al, %eax
        andl $1, %eax
        ret

Testcase here: Regression/CodeGen/X86/compare-add.ll

nukage of the and coming up next.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25898 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-02 06:36:13 +00:00
Nate Begeman
750ac1bdfa Fix some of the stuff in the PPC README file, and clean up legalization
of the SELECT_CC, BR_CC, and BRTWOWAY_CC nodes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25875 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-01 07:19:44 +00:00