1 files changed, 82 insertions, 1 deletions
diff --git a/test/Transforms/SROA/slice-width.ll b/test/Transforms/SROA/slice-width.ll
index 179780b..ff66dcc 100644
--- a/test/Transforms/SROA/slice-width.ll
+++ b/test/Transforms/SROA/slice-width.ll
@@ -1,7 +1,8 @@
 ; RUN: opt < %s -sroa -S | FileCheck %s
-target datalayout = "e-p:64:64:64-p1:16:16:16-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-n8:16:32:64"
+target datalayout = "e-p:64:64:64-p1:16:16:16-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-f80:128-v64:64:64-v128:128:128-a0:0:64-n8:16:32:64"
 
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
+declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
 
 define void @no_split_on_non_byte_width(i32) {
 ; This tests that allocas are not split into slices that are not byte width multiple
@@ -23,3 +24,83 @@ load_i1:
   %t1 = load i1* %p1
   ret void
 }
+
+; PR18726: Check that we use memcpy and memset to fill out padding when we have
+; a slice with a simple single type whose store size is smaller than the slice
+; size.
+
+%union.Foo = type { x86_fp80, i64, i64 }
+
+@foo_copy_source = external constant %union.Foo
+@i64_sink = global i64 0
+
+define void @memcpy_fp80_padding() {
+  %x = alloca %union.Foo
+
+  ; Copy from a global.
+  %x_i8 = bitcast %union.Foo* %x to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %x_i8, i8* bitcast (%union.Foo* @foo_copy_source to i8*), i32 32, i32 16, i1 false)
+
+  ; Access a slice of the alloca to trigger SROA.
+  %mid_p = getelementptr %union.Foo* %x, i32 0, i32 1
+  %elt = load i64* %mid_p
+  store i64 %elt, i64* @i64_sink
+  ret void
+}
+; CHECK-LABEL: define void @memcpy_fp80_padding
+; CHECK: alloca x86_fp80
+; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32
+; CHECK: load i64* getelementptr inbounds (%union.Foo* @foo_copy_source, i64 0, i32 1)
+; CHECK: load i64* getelementptr inbounds (%union.Foo* @foo_copy_source, i64 0, i32 2)
+
+define void @memset_fp80_padding() {
+  %x = alloca %union.Foo
+
+  ; Set to all ones.
+  %x_i8 = bitcast %union.Foo* %x to i8*
+  call void @llvm.memset.p0i8.i32(i8* %x_i8, i8 -1, i32 32, i32 16, i1 false)
+
+  ; Access a slice of the alloca to trigger SROA.
+  %mid_p = getelementptr %union.Foo* %x, i32 0, i32 1
+  %elt = load i64* %mid_p
+  store i64 %elt, i64* @i64_sink
+  ret void
+}
+; CHECK-LABEL: define void @memset_fp80_padding
+; CHECK: alloca x86_fp80
+; CHECK: call void @llvm.memset.p0i8.i32(i8* %{{.*}}, i8 -1, i32 16, i32 16, i1 false)
+; CHECK: store i64 -1, i64* @i64_sink
+
+%S.vec3float = type { float, float, float }
+%U.vec3float = type { <4 x float> }
+
+declare i32 @memcpy_vec3float_helper(%S.vec3float*)
+
+define i32 @memcpy_vec3float_widening(%S.vec3float* %x) {
+; CHECK-LABEL: @memcpy_vec3float_widening(
+; PR18726: Check that SROA does not rewrite a 12-byte memcpy into a 16-byte
+; vector store, hence accidentally putting gibberish onto the stack.
+entry:
+  ; Create a temporary variable %tmp1 and copy %x[0] into it
+  %tmp1 = alloca %S.vec3float, align 4
+  %0 = bitcast %S.vec3float* %tmp1 to i8*
+  %1 = bitcast %S.vec3float* %x to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %0, i8* %1, i32 12, i32 4, i1 false)
+
+  ; The following block does nothing; but appears to confuse SROA
+  %unused1 = bitcast %S.vec3float* %tmp1 to %U.vec3float*
+  %unused2 = getelementptr inbounds %U.vec3float* %unused1, i32 0, i32 0
+  %unused3 = load <4 x float>* %unused2, align 1
+
+  ; Create a second temporary and copy %tmp1 into it
+  %tmp2 = alloca %S.vec3float, align 4
+  %2 = bitcast %S.vec3float* %tmp2 to i8*
+  %3 = bitcast %S.vec3float* %tmp1 to i8*
+; CHECK: alloca
+; CHECK-NOT: store <4 x float>
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %2, i8* %3, i32 12, i32 4, i1 false)
+
+  %result = call i32 @memcpy_vec3float_helper(%S.vec3float* %tmp2)
+  ret i32 %result
+; CHECK: ret i32 %result
+}