LoopVectorizer:

1. Add code to estimate register pressure.
2. Add code to select the unroll factor based on register pressure.
3. Add bits to TargetTransformInfo to provide the number of registers.

llvm-svn: 171469

2 files changed, 58 insertions, 2 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/gcc-examples.ll b/llvm/test/Transforms/LoopVectorize/X86/gcc-examples.ll
index 156e7454a4c..0f21ba678c3 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/gcc-examples.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/gcc-examples.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s  -loop-vectorize -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7 -dce -instcombine -licm -S | FileCheck %s
+; RUN: opt < %s  -loop-vectorize -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7 -force-vector-unroll=0 -dce -instcombine -licm -S | FileCheck %s -check-prefix=UNROLL
 
 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-apple-macosx10.8.0"
@@ -13,6 +14,15 @@ target triple = "x86_64-apple-macosx10.8.0"
 ;CHECK: add nsw <4 x i32>
 ;CHECK: store <4 x i32>
 ;CHECK: ret void
+
+;UNROLL: @example1
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: ret void
 define void @example1() nounwind uwtable ssp {
   br label %1
 
@@ -34,13 +44,20 @@ define void @example1() nounwind uwtable ssp {
   ret void
 }
 
-
-; Select VF=4 because sext <8 x i1> to <8 x i32> is expensive. 
+; Select VF=4 because sext <8 x i1> to <8 x i32> is expensive.
 ;CHECK: @example10b
 ;CHECK: load <4 x i16>
 ;CHECK: sext <4 x i16>
 ;CHECK: store <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example10b
+;UNROLL: load <4 x i16>
+;UNROLL: load <4 x i16>
+;UNROLL: load <4 x i16>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: ret void
 define void @example10b(i16* noalias nocapture %sa, i16* noalias nocapture %sb, i16* noalias nocapture %sc, i32* noalias nocapture %ia, i32* noalias nocapture %ib, i32* noalias nocapture %ic) nounwind uwtable ssp {
   br label %1
 
diff --git a/llvm/test/Transforms/LoopVectorize/gcc-examples.ll b/llvm/test/Transforms/LoopVectorize/gcc-examples.ll
index b0f5a80d1e6..652c2a0d025 100644
--- a/llvm/test/Transforms/LoopVectorize/gcc-examples.ll
+++ b/llvm/test/Transforms/LoopVectorize/gcc-examples.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s  -loop-vectorize -force-vector-width=4 -dce -instcombine -licm -S | FileCheck %s
+; RUN: opt < %s  -loop-vectorize -force-vector-width=4 -force-vector-unroll=4 -dce -instcombine -licm -S | FileCheck %s -check-prefix=UNROLL
 
 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-apple-macosx10.8.0"
@@ -24,6 +25,20 @@ target triple = "x86_64-apple-macosx10.8.0"
 ;CHECK: add nsw <4 x i32>
 ;CHECK: store <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example1
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: add nsw <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: ret void
 define void @example1() nounwind uwtable ssp {
   br label %1
 
@@ -48,6 +63,12 @@ define void @example1() nounwind uwtable ssp {
 ;CHECK: @example2
 ;CHECK: store <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example2
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: ret void
 define void @example2(i32 %n, i32 %x) nounwind uwtable ssp {
   %1 = icmp sgt i32 %n, 0
   br i1 %1, label %.lr.ph5, label %.preheader
@@ -92,6 +113,12 @@ define void @example2(i32 %n, i32 %x) nounwind uwtable ssp {
 ;CHECK: @example3
 ;CHECK: <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example3
+;UNROLL: <4 x i32>
+;UNROLL: <4 x i32>
+;UNROLL: <4 x i32>
+;UNROLL: <4 x i32>
+;UNROLL: ret void
 define void @example3(i32 %n, i32* noalias nocapture %p, i32* noalias nocapture %q) nounwind uwtable ssp {
   %1 = icmp eq i32 %n, 0
   br i1 %1, label %._crit_edge, label %.lr.ph
@@ -115,6 +142,12 @@ define void @example3(i32 %n, i32* noalias nocapture %p, i32* noalias nocapture
 ;CHECK: @example4
 ;CHECK: load <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example4
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: load <4 x i32>
+;UNROLL: ret void
 define void @example4(i32 %n, i32* noalias nocapture %p, i32* noalias nocapture %q) nounwind uwtable ssp {
   %1 = add nsw i32 %n, -1
   %2 = icmp eq i32 %n, 0
@@ -175,6 +208,12 @@ define void @example4(i32 %n, i32* noalias nocapture %p, i32* noalias nocapture
 ;CHECK: @example8
 ;CHECK: store <4 x i32>
 ;CHECK: ret void
+;UNROLL: @example8
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: store <4 x i32>
+;UNROLL: ret void
 define void @example8(i32 %x) nounwind uwtable ssp {
   br label %.preheader