[MergedLoadStoreMotion] Add tests for store without GEPs (NFC)

MergedLoadStoreMotion currently only handles the case where each
store has it's own GEP. It fails to handle the case where the
store argument is exactly the same.

diff --git a/llvm/test/Transforms/MergedLoadStoreMotion/st_sink_no_gep.ll b/llvm/test/Transforms/MergedLoadStoreMotion/st_sink_no_gep.ll
new file mode 100644 (file)
index 0000000..854ba9e
--- /dev/null
+++ b/llvm/test/Transforms/MergedLoadStoreMotion/st_sink_no_gep.ll
@@ -0,0 +1,120 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=mldst-motion -S < %s | FileCheck %s
+;target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+
+define void @no_gep_same_ptr(i1 %c, ptr %p, i32 %x, i32 %y) {
+; CHECK-LABEL: @no_gep_same_ptr(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 [[X:%.*]], ptr [[P:%.*]], align 4
+; CHECK-NEXT:    br label [[IF_END:%.*]]
+; CHECK:       if.else:
+; CHECK-NEXT:    store i32 [[Y:%.*]], ptr [[P]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br i1 %c, label %if.then, label %if.else
+
+if.then:
+  store i32 %x, ptr %p
+  br label %if.end
+
+if.else:
+  store i32 %y, ptr %p
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+define void @no_gep_different_ptr(i1 %c, ptr %p1, ptr %p2, i32 %x, i32 %y) {
+; CHECK-LABEL: @no_gep_different_ptr(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 [[X:%.*]], ptr [[P1:%.*]], align 4
+; CHECK-NEXT:    br label [[IF_END:%.*]]
+; CHECK:       if.else:
+; CHECK-NEXT:    store i32 [[Y:%.*]], ptr [[P2:%.*]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br i1 %c, label %if.then, label %if.else
+
+if.then:
+  store i32 %x, ptr %p1
+  br label %if.end
+
+if.else:
+  store i32 %y, ptr %p2
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+define void @shared_gep(i1 %c, ptr %p, i32 %x, i32 %y) {
+; CHECK-LABEL: @shared_gep(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i32, ptr [[P:%.*]], i32 1
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 [[X:%.*]], ptr [[GEP]], align 4
+; CHECK-NEXT:    br label [[IF_END:%.*]]
+; CHECK:       if.else:
+; CHECK-NEXT:    store i32 [[Y:%.*]], ptr [[GEP]], align 4
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %gep = getelementptr i32, ptr %p, i32 1
+  br i1 %c, label %if.then, label %if.else
+
+if.then:
+  store i32 %x, ptr %gep
+  br label %if.end
+
+if.else:
+  store i32 %y, ptr %gep
+  br label %if.end
+
+if.end:
+  ret void
+}
+
+define void @separate_geps(i1 %c, ptr %p, i32 %x, i32 %y) {
+; CHECK-LABEL: @separate_geps(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    br label [[IF_END:%.*]]
+; CHECK:       if.else:
+; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end:
+; CHECK-NEXT:    [[Y_SINK:%.*]] = phi i32 [ [[X:%.*]], [[IF_THEN]] ], [ [[Y:%.*]], [[IF_ELSE]] ]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i32, ptr [[P:%.*]], i32 1
+; CHECK-NEXT:    store i32 [[Y_SINK]], ptr [[TMP0]], align 4
+; CHECK-NEXT:    ret void
+;
+entry:
+  br i1 %c, label %if.then, label %if.else
+
+if.then:
+  %gep1 = getelementptr i32, ptr %p, i32 1
+  store i32 %x, ptr %gep1
+  br label %if.end
+
+if.else:
+  %gep2 = getelementptr i32, ptr %p, i32 1
+  store i32 %y, ptr %gep2
+  br label %if.end
+
+if.end:
+  ret void
+}