Add #pragma vectorize enable/disable to LLVM

The intended behaviour is to force vectorization on the presence
of the flag (either turn on or off), and to continue the behaviour
as expected in its absence. Tests were added to make sure the all
cases are covered in opt. No tests were added in other tools with
the assumption that they should use the PassManagerBuilder in the
same way.

This patch also removes the outdated -late-vectorize flag, which was
on by default and not helping much.

The pragma metadata is being attached to the same place as other loop
metadata, but nothing forbids one from attaching it to a function
(to enable #pragma optimize) or basic blocks (to hint the basic-block
vectorizers), etc. The logic should be the same all around.

Patches to Clang to produce the metadata will be produced after the
initial implementation is agreed upon and committed. Patches to other
vectorizers (such as SLP and BB) will be added once we're happy with
the pass manager changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196537 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 175 insertions, 0 deletions

diff --git a/test/Transforms/LoopVectorize/metadata-enable.ll b/test/Transforms/LoopVectorize/metadata-enable.ll
new file mode 100644
index 0000000000..fff3c0e808
--- /dev/null
+++ b/test/Transforms/LoopVectorize/metadata-enable.ll
@@ -0,0 +1,175 @@
+; RUN: opt < %s -O1 -S | FileCheck %s --check-prefix=O1
+; RUN: opt < %s -O2 -S | FileCheck %s --check-prefix=O2
+; RUN: opt < %s -O3 -S | FileCheck %s --check-prefix=O3
+; RUN: opt < %s -Os -S | FileCheck %s --check-prefix=Os
+; RUN: opt < %s -Oz -S | FileCheck %s --check-prefix=Oz
+; RUN: opt < %s -O1 -vectorize-loops -S | FileCheck %s --check-prefix=O1VEC
+; RUN: opt < %s -Oz -vectorize-loops -S | FileCheck %s --check-prefix=OzVEC
+; RUN: opt < %s -O1 -loop-vectorize -S | FileCheck %s --check-prefix=O1VEC2
+; RUN: opt < %s -Oz -loop-vectorize -S | FileCheck %s --check-prefix=OzVEC2
+; RUN: opt < %s -O3 -disable-loop-vectorization -S | FileCheck %s --check-prefix=O3DIS
+
+; This file tests the llvm.vectorizer.pragma forcing vectorization even when
+; optimization levels are too low, or when vectorization is disabled.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; O1-LABEL: @enabled(
+; O1: store <4 x i32>
+; O1: ret i32
+; O2-LABEL: @enabled(
+; O2: store <4 x i32>
+; O2: ret i32
+; O3-LABEL: @enabled(
+; O3: store <4 x i32>
+; O3: ret i32
+; Pragma always wins!
+; O3DIS-LABEL: @enabled(
+; O3DIS: store <4 x i32>
+; O3DIS: ret i32
+; Os-LABEL: @enabled(
+; Os: store <4 x i32>
+; Os: ret i32
+; Oz-LABEL: @enabled(
+; Oz: store <4 x i32>
+; Oz: ret i32
+; O1VEC-LABEL: @enabled(
+; O1VEC: store <4 x i32>
+; O1VEC: ret i32
+; OzVEC-LABEL: @enabled(
+; OzVEC: store <4 x i32>
+; OzVEC: ret i32
+; O1VEC2-LABEL: @enabled(
+; O1VEC2: store <4 x i32>
+; O1VEC2: ret i32
+; OzVEC2-LABEL: @enabled(
+; OzVEC2: store <4 x i32>
+; OzVEC2: ret i32
+
+define i32 @enabled(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32 %N) {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds i32* %b, i64 %indvars.iv
+  %0 = load i32* %arrayidx, align 4
+  %add = add nsw i32 %0, %N
+  %arrayidx2 = getelementptr inbounds i32* %a, i64 %indvars.iv
+  store i32 %add, i32* %arrayidx2, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 32
+  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0
+
+for.end:                                          ; preds = %for.body
+  %1 = load i32* %a, align 4
+  ret i32 %1
+}
+
+; O1-LABEL: @nopragma(
+; O1-NOT: store <4 x i32>
+; O1: ret i32
+; O2-LABEL: @nopragma(
+; O2: store <4 x i32>
+; O2: ret i32
+; O3-LABEL: @nopragma(
+; O3: store <4 x i32>
+; O3: ret i32
+; O3DIS-LABEL: @nopragma(
+; O3DIS-NOT: store <4 x i32>
+; O3DIS: ret i32
+; Os-LABEL: @nopragma(
+; Os: store <4 x i32>
+; Os: ret i32
+; Oz-LABEL: @nopragma(
+; Oz-NOT: store <4 x i32>
+; Oz: ret i32
+; O1VEC-LABEL: @nopragma(
+; O1VEC: store <4 x i32>
+; O1VEC: ret i32
+; OzVEC-LABEL: @nopragma(
+; OzVEC: store <4 x i32>
+; OzVEC: ret i32
+; O1VEC2-LABEL: @nopragma(
+; O1VEC2: store <4 x i32>
+; O1VEC2: ret i32
+; OzVEC2-LABEL: @nopragma(
+; OzVEC2: store <4 x i32>
+; OzVEC2: ret i32
+
+define i32 @nopragma(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32 %N) {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds i32* %b, i64 %indvars.iv
+  %0 = load i32* %arrayidx, align 4
+  %add = add nsw i32 %0, %N
+  %arrayidx2 = getelementptr inbounds i32* %a, i64 %indvars.iv
+  store i32 %add, i32* %arrayidx2, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 32
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  %1 = load i32* %a, align 4
+  ret i32 %1
+}
+
+; O1-LABEL: @disabled(
+; O1-NOT: store <4 x i32>
+; O1: ret i32
+; O2-LABEL: @disabled(
+; O2-NOT: store <4 x i32>
+; O2: ret i32
+; O3-LABEL: @disabled(
+; O3-NOT: store <4 x i32>
+; O3: ret i32
+; O3DIS-LABEL: @disabled(
+; O3DIS-NOT: store <4 x i32>
+; O3DIS: ret i32
+; Os-LABEL: @disabled(
+; Os-NOT: store <4 x i32>
+; Os: ret i32
+; Oz-LABEL: @disabled(
+; Oz-NOT: store <4 x i32>
+; Oz: ret i32
+; O1VEC-LABEL: @disabled(
+; O1VEC-NOT: store <4 x i32>
+; O1VEC: ret i32
+; OzVEC-LABEL: @disabled(
+; OzVEC-NOT: store <4 x i32>
+; OzVEC: ret i32
+; O1VEC2-LABEL: @disabled(
+; O1VEC2-NOT: store <4 x i32>
+; O1VEC2: ret i32
+; OzVEC2-LABEL: @disabled(
+; OzVEC2-NOT: store <4 x i32>
+; OzVEC2: ret i32
+
+define i32 @disabled(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i32 %N) {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds i32* %b, i64 %indvars.iv
+  %0 = load i32* %arrayidx, align 4
+  %add = add nsw i32 %0, %N
+  %arrayidx2 = getelementptr inbounds i32* %a, i64 %indvars.iv
+  store i32 %add, i32* %arrayidx2, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 32
+  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !2
+
+for.end:                                          ; preds = %for.body
+  %1 = load i32* %a, align 4
+  ret i32 %1
+}
+
+!0 = metadata !{metadata !0, metadata !1}
+!1 = metadata !{metadata !"llvm.vectorizer.enable", i1 1}
+!2 = metadata !{metadata !2, metadata !3}
+!3 = metadata !{metadata !"llvm.vectorizer.enable", i1 0}
\ No newline at end of file