From 287fa2e16432c57b6127784c09b19817c33c3e51 Mon Sep 17 00:00:00 2001
From: Anna Thomas <anna@azul.com>
Date: Mon, 6 Dec 2021 16:31:02 -0500
Subject: [PATCH] Update with additional tests for sinking calls to uses

Precommitted from D109917.
Note that the log call is already handled by instCombine.
---
 .../Transforms/InstCombine/sink_instruction.ll     | 21 +++++
 .../InstCombine/sink_sideeffecting_instruction.ll  | 93 ++++++++++++++++++++++
 2 files changed, 114 insertions(+)
 create mode 100644 llvm/test/Transforms/InstCombine/sink_sideeffecting_instruction.ll

diff --git a/llvm/test/Transforms/InstCombine/sink_instruction.ll b/llvm/test/Transforms/InstCombine/sink_instruction.ll
index a9aba31..1c28ef9 100644
--- a/llvm/test/Transforms/InstCombine/sink_instruction.ll
+++ b/llvm/test/Transforms/InstCombine/sink_instruction.ll
@@ -216,3 +216,24 @@ sw.epilog:                                        ; preds = %entry, %sw.bb
   ret i32 %sum.0
 }
 
+declare void @checkd(double)
+declare double @log(double) willreturn nounwind readnone
+define void @test7(i1 %cond, double %d) {
+; CHECK-LABEL: @test7(
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    [[A:%.*]] = call double @log(double [[D:%.*]])
+; CHECK-NEXT:    call void @checkd(double [[A]])
+; CHECK-NEXT:    ret void
+; CHECK:       else:
+; CHECK-NEXT:    ret void
+;
+  %A = call double @log(double %d)
+  br i1 %cond, label %if, label %else
+
+if:
+  call void @checkd(double %A)
+  ret void
+else:
+  ret void
+}
diff --git a/llvm/test/Transforms/InstCombine/sink_sideeffecting_instruction.ll b/llvm/test/Transforms/InstCombine/sink_sideeffecting_instruction.ll
new file mode 100644
index 0000000..e36256e
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/sink_sideeffecting_instruction.ll
@@ -0,0 +1,93 @@
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+; Function Attrs: noinline uwtable
+define dso_local i32 @foo(i32* nocapture writeonly %arg) local_unnamed_addr #0 {
+bb:
+  %tmp = call i32 @baz()
+  store i32 %tmp, i32* %arg, align 4, !tbaa !2
+  %tmp1 = call i32 @baz()
+  ret i32 %tmp1
+}
+declare dso_local i32 @baz() local_unnamed_addr
+
+; Function Attrs: uwtable
+; This is an equivalent IR for a c-style example with a large function (foo)
+; with out-params which are unused in the caller(test8). Note that foo is
+; marked noinline to prevent IPO transforms.
+; int foo();
+; 
+; extern int foo(int *out) __attribute__((noinline));
+; int foo(int *out) {
+;   *out = baz();
+;   return baz();
+; }
+; 
+; int test() {
+; 
+;   int notdead;
+;   if (foo(&notdead))
+;     return 0;
+; 
+;   int dead;
+;   int tmp = foo(&dead);
+;   if (notdead)
+;     return tmp;
+;   return bar();
+; }
+
+; TODO: We should be able to sink the second call @foo at bb5 down to bb_crit_edge 
+define dso_local i32 @test() local_unnamed_addr #2 {
+; CHECK-LABEL: test
+; CHECK: bb5:
+; CHECK: %tmp7 = call i32 @foo(i32* nonnull writeonly %tmp1) 
+; CHECK: br i1 %tmp9, label %bb10, label %bb_crit_edge
+bb:
+  %tmp = alloca i32, align 4
+  %tmp1 = alloca i32, align 4
+  %tmp2 = bitcast i32* %tmp to i8*
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %tmp2) #4
+  %tmp3 = call i32 @foo(i32* nonnull writeonly %tmp)
+  %tmp4 = icmp eq i32 %tmp3, 0
+  br i1 %tmp4, label %bb5, label %bb14
+
+bb5:                                              ; preds = %bb
+  %tmp6 = bitcast i32* %tmp1 to i8*
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %tmp6) #4
+  %tmp7 = call i32 @foo(i32* nonnull writeonly %tmp1)
+  %tmp8 = load i32, i32* %tmp, align 4, !tbaa !2
+  %tmp9 = icmp eq i32 %tmp8, 0
+  br i1 %tmp9, label %bb10, label %bb_crit_edge
+
+bb10:                                             ; preds = %bb5
+  %tmp11 = call i32 @bar()
+  br label %bb12
+
+bb_crit_edge:
+  br label %bb12
+
+bb12:                                             ; preds = %bb10, %bb5
+  %tmp13 = phi i32 [ %tmp11, %bb10 ], [ %tmp7, %bb_crit_edge ]
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %tmp6) #4
+  br label %bb14
+
+bb14:                                             ; preds = %bb12, %bb
+  %tmp15 = phi i32 [ %tmp13, %bb12 ], [ 0, %bb ]
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %tmp2)
+  ret i32 %tmp15
+}
+
+declare i32 @bar()
+; Function Attrs: argmemonly nofree nosync nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #3
+
+; Function Attrs: argmemonly nofree nosync nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #3
+
+attributes #0 = { noinline uwtable argmemonly nounwind willreturn }
+attributes #3 = { argmemonly nofree nosync nounwind willreturn }
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 10.0.0-4ubuntu1 "}
+!2 = !{!3, !3, i64 0}
+!3 = !{!"int", !4, i64 0}
+!4 = !{!"omnipotent char", !5, i64 0}
+!5 = !{!"Simple C++ TBAA"}
-- 
2.7.4