Commit Graph

11 Commits

Author SHA1 Message Date
Quentin Colombet b4d53f1afa [X86] Fix a bug in the lowering of BLENDI introduced in r209043.
ISD::VSELECT mask uses 1 to identify the first argument and 0 to identify the
second argument.
On the other hand, BLENDI uses 0 to identify the first argument and 1 to
identify the second argument.
Fix the generation of the blend mask to account for this difference.

The bug did not show up with r209043, because we were not checking for the
actual arguments of the blend instruction!
This commit also fixes the test cases.

Note: The same mask works for the BLENDr variant because the arguments are
swapped during instruction selection (see the BLENDXXrr patterns).

<rdar://problem/16975435>

llvm-svn: 209324
2014-05-21 22:00:39 +00:00
Filipe Cabecinhas e15551832c Lower vselects into X86ISD::BLENDI when appropriate.
LowerVSELECT will, if possible, generate a X86ISD::BLENDI DAG node if the
condition is constant and we can emit that instruction, given the
subtarget.

This is not enough for all cases. An additional SELECTCombine optimization
will be committed.

Fixed tests that were expecting variable blends but where a blend+imm can
be generated.
Added test where we can't emit blend+immediate.
Added avx2 blend+imm tests.

llvm-svn: 209043
2014-05-16 22:47:49 +00:00
Andrea Di Biagio 450d1661be [X86] Teach how to combine a vselect into a movss/movsd
Add target specific rules for combining vselect dag nodes into movss/movsd
when possible.

If the vector type of the vselect dag node in input is either MVT::v4i13 or
MVT::v4f32, then try to fold according to rules:

  1) fold (vselect (build_vector (0, -1, -1, -1)), A, B) -> (movss A, B)
  2) fold (vselect (build_vector (-1, 0, 0, 0)), A, B) -> (movss B, A)

If the vector type of the vselect dag node in input is either MVT::v2i64 or
MVT::v2f64 (and we have SSE2), then try to fold according to rules:

  3) fold (vselect (build_vector (0, -1)), A, B) -> (movsd A, B)
  4) fold (vselect (build_vector (-1, 0)), A, B) -> (movsd B, A)

llvm-svn: 199683
2014-01-20 19:35:22 +00:00
Andrea Di Biagio 46dcddb350 Teach DAGCombiner how to fold a SIGN_EXTEND_INREG of a BUILD_VECTOR of
ConstantSDNodes (or UNDEFs) into a simple BUILD_VECTOR.

For example, given the following sequence of dag nodes:

  i32 C = Constant<1>
  v4i32 V = BUILD_VECTOR C, C, C, C
  v4i32 Result = SIGN_EXTEND_INREG V, ValueType:v4i1

The SIGN_EXTEND_INREG node can be folded into a build_vector since
the vector in input is a BUILD_VECTOR of constants.

The optimized sequence is:

  i32 C = Constant<-1>
  v4i32 Result = BUILD_VECTOR C, C, C, C

llvm-svn: 198084
2013-12-27 20:20:28 +00:00
Rafael Espindola ae6000e86d Replace more uses of sse41 with sse4.1.
llc using the host cpu features and *waning* on unknown features is probably
not a good thing :-(

llvm-svn: 189144
2013-08-23 20:39:19 +00:00
Stephen Lin 6f36b45076 Update to more CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change.
All changes were made by the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    grep -q "^; *RUN: *llc.*debug" $NAME && continue
    grep -q "^; *RUN:.*llvm-objdump" $NAME && continue
    grep -q "^; *RUN: *opt.*" $NAME && continue
    TEMP=`mktemp -t temp`
    cp $NAME $TEMP
    sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
    while read FUNC; do
      sed -i '' "s/;\([A-Za-z0-9_-]*\)\([A-Za-z0-9_-]*\):\( *\)$FUNC[:]* *\$/;\1\2-LABEL:\3$FUNC:/g" $TEMP
    done
    sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
    sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
    sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
    sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
    mv $TEMP $NAME
  done

This script catches a superset of the cases caught by the script associated with commit r186280. It initially found some false positives due to unusual constructs in a minority of tests; all such cases were disambiguated first in commit r186621.

llvm-svn: 186624
2013-07-18 22:47:09 +00:00
Nadav Rotem b532fca92c Revert r169638 because it broke Mesa llvmpipe tests.
Fix PR15239.

llvm-svn: 175985
2013-02-24 07:09:35 +00:00
Benjamin Kramer 548ffa274a SelectionDAG: Teach FoldConstantArithmetic how to deal with vectors.
This required disabling a PowerPC optimization that did the following:
input:
x = BUILD_VECTOR <i32 16, i32 16, i32 16, i32 16>
lowered to:
tmp = BUILD_VECTOR <i32 8, i32 8, i32 8, i32 8>
x = ADD tmp, tmp

The add now gets folded immediately and we're back at the BUILD_VECTOR we
started from. I don't see a way to fix this currently so I left it disabled
for now.

Fix some trivially foldable X86 tests too.

llvm-svn: 174325
2013-02-04 15:19:18 +00:00
Nadav Rotem ad0b5fbe8c When we use the BLEND instruction that uses the MSB as a mask, we can remove
the VSRI instruction before it since it does not affect the MSB.

Thanks Craig Topper for suggesting this.

llvm-svn: 169638
2012-12-07 21:43:11 +00:00
Nadav Rotem b7bb72e4f3 Remove the "-promote-elements" flag. This flag is now enabled by default.
llvm-svn: 157925
2012-06-04 11:27:21 +00:00
Nadav Rotem 57935243bd [AVX] Optimize x86 VSELECT instructions using SimplifyDemandedBits.
We know that the blend instructions only use the MSB, so if the mask is
sign-extended then we can convert it into a SHL instruction. This is a
common pattern because the type-legalizer sign-extends the i1 type which
is used by the LLVM-IR for the condition.

Added a new optimization in SimplifyDemandedBits for SIGN_EXTEND_INREG -> SHL.

llvm-svn: 148225
2012-01-15 19:27:55 +00:00