Vector Clone Tests for the loop vectorizer

[fpetrogalli]

Summary

These tests check the Loop Vectorizer interface with the Vector Clone pass on some of the x86 vector extensions.

In particular, they make sure that the correct vector function is selected when targeting each of the extensions.

The test is based on the work in progress patches at:

https://reviews.llvm.org/D40577
https://reviews.llvm.org/D40575
https://reviews.llvm.org/D22792

test/Transforms/LoopVectorize/vector-variant/loop-x86.ll

+; RUN: opt < %s -S  -loop-vectorize -force-vector-interleave=1 -mattr=+sse \
+; RUN:     | FileCheck %s --check-prefix=SSE
+
+; RUN: opt < %s -S  -loop-vectorize -force-vector-interleave=1 -mattr=+avx \
+; RUN:     | FileCheck %s --check-prefix=AVX
+
+; RUN: opt < %s -S  -loop-vectorize -force-vector-interleave=1 -mattr=+avx2 \
+; RUN:     | FileCheck %s --check-prefix=AVX2
+
+; RUN: opt < %s -S  -loop-vectorize -force-vector-interleave=1 -mattr=+avx512f \
+; RUN:     | FileCheck %s --check-prefix=AVX512
+
+; This is targeting SSE, the other vector extensions are not used.
+; SSE-NOT: @_ZGVc
+; SSE-NOT: @_ZGVd
+; SSE-NOT: @_ZGVe
+; SSE-LABEL: void @loop
+; SSE: call <2 x double> @_ZGVbN2v_foo
+
+; This is targeting AVX, the other vector extensions are not used.
+; AVX-NOT: @_ZGVb
+; AVX-NOT: @_ZGVd
+; AVX-NOT: @_ZGVe
+; AVX-LABEL: void @loop
+; AVX: call <4 x double> @_ZGVcN4v_foo
+
+; This is targeting AVX2, the other vector extensions are not used.
+; AVX2-NOT: @_ZGVb
+; AVX2-NOT: @_ZGVc
+; AVX2-NOT: @_ZGVe
+; AVX2-LABEL: void @loop
+; AVX2: call <4 x double> @_ZGVdN4v_foo
+
+; This is targeting AVX512, the other vector extensions are not used.
+; AVX512-NOT: @_ZGVb
+; AVX512-NOT: @_ZGVc
+; AVX512-NOT: @_ZGVd
+; AVX512-LABEL: void @loop
+; AVX512: call <8 x double> @_ZGVeN8v_foo
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define double @foo(double %x) #0 {
+entry:
+  %mul = fmul double %x, 2.000000e+00
+  %add = fadd double %mul, 1.000000e+00
+  ret double %add
+}
+
+define void @loop(double* noalias nocapture readonly %x, double* nocapture %y, i32 %n) {
+entry:
+  %cmp9 = icmp eq i32 %n, 0
+  br i1 %cmp9, label %for.cond.cleanup, label %for.body.preheader
+
+for.body.preheader:                               ; preds = %entry
+  %wide.trip.count = zext i32 %n to i64
+  br label %for.body
+
+for.cond.cleanup:                                 ; preds = %for.body, %entry
+  ret void
+
+for.body:                                         ; preds = %for.body, %for.body.preheader
+  %indvars.iv = phi i64 [ 0, %for.body.preheader ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds double, double* %x, i64 %indvars.iv
+  %0 = load double, double* %arrayidx, align 8 
+  %call = tail call double @foo(double %0)
+  %arrayidx3 = getelementptr inbounds double, double* %y, i64 %indvars.iv
+  store double %call, double* %arrayidx3, align 8
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count
+  br i1 %exitcond, label %for.cond.cleanup, label %for.body
+}
+
+attributes #0 = { noinline "vector-variants"="_ZGVbN2v_foo, _ZGVcN4v_foo, _ZGVdN4v_foo, _ZGVeN8v_foo" }