ARM cost model: Account for zero cost scalar SROA instructions

By vectorizing a series of srl, or, ... instructions we have obfuscated the
intention so much that the backend does not know how to fold this code away.

radar://15336950

llvm-svn: 193573

1 files changed, 52 insertions, 0 deletions

diff --git a/llvm/test/Transforms/SLPVectorizer/ARM/sroa.ll b/llvm/test/Transforms/SLPVectorizer/ARM/sroa.ll
new file mode 100644
index 00000000000..e0c75b147f6
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/ARM/sroa.ll
@@ -0,0 +1,52 @@
+; RUN: opt -S -mcpu=swift -mtriple=thumbv7-apple-ios -basicaa -slp-vectorizer < %s | FileCheck %s
+
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
+
+%class.Complex = type { double, double }
+
+; Code like this is the result of SROA. Make sure we don't vectorize this
+; because the in the scalar version of this the shl/or are handled by the
+; backend and disappear, the vectorized code stays.
+
+; CHECK-LABEL: SROAed
+; CHECK-NOT: shl <2 x i64>
+; CHECK-NOT: or <2 x i64>
+
+define void @SROAed(%class.Complex* noalias nocapture sret %agg.result, [4 x i32] %a.coerce, [4 x i32] %b.coerce) {
+entry:
+  %a.coerce.fca.0.extract = extractvalue [4 x i32] %a.coerce, 0
+  %a.sroa.0.0.insert.ext = zext i32 %a.coerce.fca.0.extract to i64
+  %a.coerce.fca.1.extract = extractvalue [4 x i32] %a.coerce, 1
+  %a.sroa.0.4.insert.ext = zext i32 %a.coerce.fca.1.extract to i64
+  %a.sroa.0.4.insert.shift = shl nuw i64 %a.sroa.0.4.insert.ext, 32
+  %a.sroa.0.4.insert.insert = or i64 %a.sroa.0.4.insert.shift, %a.sroa.0.0.insert.ext
+  %0 = bitcast i64 %a.sroa.0.4.insert.insert to double
+  %a.coerce.fca.2.extract = extractvalue [4 x i32] %a.coerce, 2
+  %a.sroa.3.8.insert.ext = zext i32 %a.coerce.fca.2.extract to i64
+  %a.coerce.fca.3.extract = extractvalue [4 x i32] %a.coerce, 3
+  %a.sroa.3.12.insert.ext = zext i32 %a.coerce.fca.3.extract to i64
+  %a.sroa.3.12.insert.shift = shl nuw i64 %a.sroa.3.12.insert.ext, 32
+  %a.sroa.3.12.insert.insert = or i64 %a.sroa.3.12.insert.shift, %a.sroa.3.8.insert.ext
+  %1 = bitcast i64 %a.sroa.3.12.insert.insert to double
+  %b.coerce.fca.0.extract = extractvalue [4 x i32] %b.coerce, 0
+  %b.sroa.0.0.insert.ext = zext i32 %b.coerce.fca.0.extract to i64
+  %b.coerce.fca.1.extract = extractvalue [4 x i32] %b.coerce, 1
+  %b.sroa.0.4.insert.ext = zext i32 %b.coerce.fca.1.extract to i64
+  %b.sroa.0.4.insert.shift = shl nuw i64 %b.sroa.0.4.insert.ext, 32
+  %b.sroa.0.4.insert.insert = or i64 %b.sroa.0.4.insert.shift, %b.sroa.0.0.insert.ext
+  %2 = bitcast i64 %b.sroa.0.4.insert.insert to double
+  %b.coerce.fca.2.extract = extractvalue [4 x i32] %b.coerce, 2
+  %b.sroa.3.8.insert.ext = zext i32 %b.coerce.fca.2.extract to i64
+  %b.coerce.fca.3.extract = extractvalue [4 x i32] %b.coerce, 3
+  %b.sroa.3.12.insert.ext = zext i32 %b.coerce.fca.3.extract to i64
+  %b.sroa.3.12.insert.shift = shl nuw i64 %b.sroa.3.12.insert.ext, 32
+  %b.sroa.3.12.insert.insert = or i64 %b.sroa.3.12.insert.shift, %b.sroa.3.8.insert.ext
+  %3 = bitcast i64 %b.sroa.3.12.insert.insert to double
+  %add = fadd double %0, %2
+  %add3 = fadd double %1, %3
+  %re.i.i = getelementptr inbounds %class.Complex* %agg.result, i32 0, i32 0
+  store double %add, double* %re.i.i, align 4
+  %im.i.i = getelementptr inbounds %class.Complex* %agg.result, i32 0, i32 1
+  store double %add3, double* %im.i.i, align 4
+  ret void
+}