[X86] AVX512: Enable it in the Loop Vectorizer

This lets us experiment with 512-bit vectorization without passing
force-vector-width manually.

The code generated for a simple integer memset loop is properly vectorized.
Disassembly is still broken for it though :(.

llvm-svn: 212634

1 files changed, 35 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/avx512.ll b/llvm/test/Transforms/LoopVectorize/X86/avx512.ll
new file mode 100644
index 00000000000..a2208668177
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/X86/avx512.ll
@@ -0,0 +1,35 @@
+; RUN: opt -mattr=+avx512f --loop-vectorize -S < %s | llc -mattr=+avx512f | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+; Verify that we generate 512-bit wide vectors for a basic integer memset
+; loop.
+
+; CHECK-LABEL: f:
+; CHECK: vmovdqu32 %zmm{{.}}, (
+; CHECK-NOT: %ymm
+
+define void @f(i32* %a, i32 %n) {
+entry:
+  %cmp4 = icmp sgt i32 %n, 0
+  br i1 %cmp4, label %for.body.preheader, label %for.end
+
+for.body.preheader:                               ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ]
+  %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
+  store i32 %n, i32* %arrayidx, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+  %exitcond = icmp eq i32 %lftr.wideiv, %n
+  br i1 %exitcond, label %for.end.loopexit, label %for.body
+
+for.end.loopexit:                                 ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  ret void
+}