[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

1 files changed, 47 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/AArch64/type-shrinkage-insertelt.ll b/llvm/test/Transforms/LoopVectorize/AArch64/type-shrinkage-insertelt.ll
new file mode 100644
index 00000000000..ffe8480138d
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/AArch64/type-shrinkage-insertelt.ll
@@ -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
+}