[LV] Add support for insertelt/extractelt processing during type truncation

Summary:
While shrinking types according to the required bits, we can
encounter insert/extract element instructions. This will cause us to
reach an llvm_unreachable statement.

This change adds support for truncating insert/extract element
operations, and adds a regression test.

Reviewers: jmolloy

Subscribers: mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D17078

llvm-svn: 260893
This commit is contained in:
Silviu Baranga 2016-02-15 15:38:17 +00:00
parent 036c08874a
commit ec7063ac77
2 changed files with 61 additions and 0 deletions

View File

@ -3187,6 +3187,9 @@ void InnerLoopVectorizer::truncateToMinimalBitwidths() {
if (TruncatedTy == OriginalTy)
continue;
if (!isa<Instruction>(I))
continue;
IRBuilder<> B(cast<Instruction>(I));
auto ShrinkOperand = [&](Value *V) -> Value* {
if (auto *ZI = dyn_cast<ZExtInst>(V))
@ -3242,6 +3245,17 @@ void InnerLoopVectorizer::truncateToMinimalBitwidths() {
} else if (isa<LoadInst>(I)) {
// Don't do anything with the operands, just extend the result.
continue;
} else if (auto *IE = dyn_cast<InsertElementInst>(I)) {
auto Elements = IE->getOperand(0)->getType()->getVectorNumElements();
auto *O0 = B.CreateZExtOrTrunc(
IE->getOperand(0), VectorType::get(ScalarTruncatedTy, Elements));
auto *O1 = B.CreateZExtOrTrunc(IE->getOperand(1), ScalarTruncatedTy);
NewI = B.CreateInsertElement(O0, O1, IE->getOperand(2));
} else if (auto *EE = dyn_cast<ExtractElementInst>(I)) {
auto Elements = EE->getOperand(0)->getType()->getVectorNumElements();
auto *O0 = B.CreateZExtOrTrunc(
EE->getOperand(0), VectorType::get(ScalarTruncatedTy, Elements));
NewI = B.CreateExtractElement(O0, EE->getOperand(2));
} else {
llvm_unreachable("Unhandled instruction type!");
}

View File

@ -0,0 +1,47 @@
; RUN: opt -S < %s -loop-vectorize -force-vector-width=4 | FileCheck %s
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
target triple = "aarch64--linux-gnu"
; CHECK-LABEL: test0
define void @test0(i16* noalias %M3) {
entry:
br label %if.then1165.us
if.then1165.us: ; preds = %if.then1165.us, %entry
%indvars.iv1783 = phi i64 [ 0, %entry ], [ %indvars.iv.next1784, %if.then1165.us ]
%conv1177.us = zext i16 undef to i32
%add1178.us = add nsw i32 %conv1177.us, undef
%conv1179.us = trunc i32 %add1178.us to i16
%idxprom1181.us = ashr exact i64 undef, 32
%arrayidx1185.us = getelementptr inbounds i16, i16* %M3, i64 %idxprom1181.us
store i16 %conv1179.us, i16* %arrayidx1185.us, align 2
%indvars.iv.next1784 = add nuw nsw i64 %indvars.iv1783, 1
%exitcond1785 = icmp eq i64 %indvars.iv.next1784, 16
br i1 %exitcond1785, label %for.inc1286.loopexit, label %if.then1165.us
for.inc1286.loopexit: ; preds = %if.then1165.us
ret void
}
; CHECK-LABEL: test1
define void @test1(i16* noalias %M3) {
entry:
br label %if.then1165.us
if.then1165.us: ; preds = %if.then1165.us, %entry
%indvars.iv1783 = phi i64 [ 0, %entry ], [ %indvars.iv.next1784, %if.then1165.us ]
%fptr = load i32, i32* undef, align 4
%conv1177.us = zext i16 undef to i32
%add1178.us = add nsw i32 %conv1177.us, %fptr
%conv1179.us = trunc i32 %add1178.us to i16
%idxprom1181.us = ashr exact i64 undef, 32
%arrayidx1185.us = getelementptr inbounds i16, i16* %M3, i64 %idxprom1181.us
store i16 %conv1179.us, i16* %arrayidx1185.us, align 2
%indvars.iv.next1784 = add nuw nsw i64 %indvars.iv1783, 1
%exitcond1785 = icmp eq i64 %indvars.iv.next1784, 16
br i1 %exitcond1785, label %for.inc1286.loopexit, label %if.then1165.us
for.inc1286.loopexit: ; preds = %if.then1165.us
ret void
}