From 4e7b015a4a724782bf37284c3c74f2540cf8f3e1 Mon Sep 17 00:00:00 2001
From: Arnold Schwaighofer <aschwaighofer@apple.com>
Date: Mon, 23 Sep 2013 14:54:39 +0000
Subject: Revert "LoopVectorizer: Only allow vectorization of intrinsics."

Revert 191122 - with extra checks we are allowed to vectorize math library
function calls.

Standard library indentifiers are reserved names so functions with external
linkage must not overrided them. However, functions with internal linkage can.

Therefore, we can vectorize calls to math library functions with a check for
external linkage and matching signature. This matches what we do during
SelectionDAG building.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191206 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/LoopVectorize/intrinsic.ll | 73 ++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 20 deletions(-)

(limited to 'test/Transforms')

diff --git a/test/Transforms/LoopVectorize/intrinsic.ll b/test/Transforms/LoopVectorize/intrinsic.ll
index 99d6646..c3d570c 100644
--- a/test/Transforms/LoopVectorize/intrinsic.ll
+++ b/test/Transforms/LoopVectorize/intrinsic.ll
@@ -1018,7 +1018,7 @@ for.body:                                         ; preds = %entry, %for.body
   %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
   %arrayidx = getelementptr inbounds float* %x, i64 %indvars.iv
   %0 = load float* %arrayidx, align 4
-  %call = tail call float @llvm.fabs.f32(float %0) nounwind readnone
+  %call = tail call float @fabsf(float %0) nounwind readnone
   store float %call, float* %arrayidx, align 4
   %indvars.iv.next = add i64 %indvars.iv, 1
   %lftr.wideiv = trunc i64 %indvars.iv.next to i32
@@ -1029,31 +1029,64 @@ for.end:                                          ; preds = %for.body
   ret void
 }
 
+declare float @fabsf(float) nounwind readnone
+
 declare double @llvm.pow.f64(double, double) nounwind readnone
 
 
-;CHECK: @not_intrin
-;CHECK: @round
-;CHECK-NOT: @round
-;CHECK: ret
-define void @not_intrin(i32* nocapture %A) nounwind ssp uwtable {
-  br label %1
-
-; <label>:1                                       ; preds = %1, %0
-  %indvars.iv = phi i64 [ 0, %0 ], [ %indvars.iv.next, %1 ]
-  %2 = getelementptr inbounds i32* %A, i64 %indvars.iv
-  %3 = load i32* %2, align 4
-  %4 = add nsw i32 %3, 3
-  store i32 %4, i32* %2, align 4
-  %5 = trunc i64 %indvars.iv to i32
-  tail call void @round(i32 %5) nounwind
+
+; Make sure we don't replace calls to functions with standard library function
+; signatures but defined with internal linkage.
+
+define internal float @roundf(float %x) nounwind readnone {
+  ret float 0.00000000
+}
+; CHECK-LABEL: internal_round
+; CHECK-NOT:  load <4 x float>
+
+define void @internal_round(float* nocapture %x) nounwind {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds float* %x, i64 %indvars.iv
+  %0 = load float* %arrayidx, align 4
+  %call = tail call float @roundf(float %0) nounwind readnone
+  store float %call, float* %arrayidx, align 4
+  %indvars.iv.next = add i64 %indvars.iv, 1
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+  %exitcond = icmp eq i32 %lftr.wideiv, 1024
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret void
+}
+
+; Make sure we don't replace calls to functions with standard library names but
+; different signatures.
+
+declare void @round(double %f)
+
+; CHECK-LABEL: wrong_signature
+; CHECK-NOT:  load <4 x double>
+
+define void @wrong_signature(double* nocapture %x) nounwind {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds double* %x, i64 %indvars.iv
+  %0 = load double* %arrayidx, align 4
+  store double %0, double* %arrayidx, align 4
+  tail call void @round(double %0) nounwind readnone
   %indvars.iv.next = add i64 %indvars.iv, 1
   %lftr.wideiv = trunc i64 %indvars.iv.next to i32
-  %exitcond = icmp eq i32 %lftr.wideiv, 256
-  br i1 %exitcond, label %6, label %1
+  %exitcond = icmp eq i32 %lftr.wideiv, 1024
+  br i1 %exitcond, label %for.end, label %for.body
 
-; <label>:6                                       ; preds = %1
+for.end:                                          ; preds = %for.body
   ret void
 }
 
-declare void @round(i32)
-- 
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