Make SROA more aggressive with allocas containing padding.

SROA only split up structs and arrays one level at a time, so padding can
only cause trouble if it is located in between the struct or array elements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123380 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 1 deletions

diff --git a/test/Transforms/ScalarRepl/copy-aggregate.ll b/test/Transforms/ScalarRepl/copy-aggregate.ll
index 2992413876..6e01aa3c51 100644
--- a/test/Transforms/ScalarRepl/copy-aggregate.ll
+++ b/test/Transforms/ScalarRepl/copy-aggregate.ll
@@ -1,9 +1,11 @@
-; RUN: opt < %s -scalarrepl -S | not grep alloca
+; RUN: opt < %s -scalarrepl -S | FileCheck %s
 ; PR3290
 target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"
 
 ;; Store of integer to whole alloca struct.
 define i32 @test1(i64 %V) nounwind {
+; CHECK: test1
+; CHECK-NOT: alloca
 	%X = alloca {{i32, i32}}
 	%Y = bitcast {{i32,i32}}* %X to i64*
 	store i64 %V, i64* %Y
@@ -18,6 +20,8 @@ define i32 @test1(i64 %V) nounwind {
 
 ;; Store of integer to whole struct/array alloca.
 define float @test2(i128 %V) nounwind {
+; CHECK: test2
+; CHECK-NOT: alloca
 	%X = alloca {[4 x float]}
 	%Y = bitcast {[4 x float]}* %X to i128*
 	store i128 %V, i128* %Y
@@ -32,6 +36,8 @@ define float @test2(i128 %V) nounwind {
 
 ;; Load of whole alloca struct as integer
 define i64 @test3(i32 %a, i32 %b) nounwind {
+; CHECK: test3
+; CHECK-NOT: alloca
 	%X = alloca {{i32, i32}}
 
 	%A = getelementptr {{i32,i32}}* %X, i32 0, i32 0, i32 0
@@ -46,6 +52,8 @@ define i64 @test3(i32 %a, i32 %b) nounwind {
 
 ;; load of integer from whole struct/array alloca.
 define i128 @test4(float %a, float %b) nounwind {
+; CHECK: test4
+; CHECK-NOT: alloca
 	%X = alloca {[4 x float]}
 	%A = getelementptr {[4 x float]}* %X, i32 0, i32 0, i32 0
 	%B = getelementptr {[4 x float]}* %X, i32 0, i32 0, i32 3
@@ -56,3 +64,22 @@ define i128 @test4(float %a, float %b) nounwind {
 	%V = load i128* %Y
 	ret i128 %V
 }
+
+;; If the elements of a struct or array alloca contain padding, SROA can still
+;; split up the alloca as long as there is no padding between the elements.
+%padded = type { i16, i8 }
+%arr = type [4 x %padded]
+define void @test5(%arr* %p, %arr* %q) {
+entry:
+; CHECK: test5
+; CHECK-NOT: i128
+  %var = alloca %arr, align 4
+  %vari8 = bitcast %arr* %var to i8*
+  %pi8 = bitcast %arr* %p to i8*
+  call void @llvm.memcpy.i32(i8* %vari8, i8* %pi8, i32 16, i32 4)
+  %qi8 = bitcast %arr* %q to i8*
+  call void @llvm.memcpy.i32(i8* %qi8, i8* %vari8, i32 16, i32 4)
+  ret void
+}
+
+declare void @llvm.memcpy.i32(i8* nocapture, i8* nocapture, i32, i32) nounwind