[Attributor] Use abstract call sites for call site callback

Summary:
When we iterate over uses of functions and expect them to be call sites,
we now use abstract call sites to allow callback calls.

Reviewers: sstefan1, uenoku

Subscribers: hiraditya, bollu, hfinkel, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67871

llvm-svn: 373985

1 files changed, 63 insertions, 0 deletions

diff --git a/llvm/test/Transforms/FunctionAttrs/callbacks.ll b/llvm/test/Transforms/FunctionAttrs/callbacks.ll
new file mode 100644
index 00000000000..3628bfa9daf
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/callbacks.ll
@@ -0,0 +1,63 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=1 < %s | FileCheck %s
+; ModuleID = 'callback_simple.c'
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+; Test 0
+;
+; Make sure we propagate information from the caller to the callback callee but
+; only for arguments that are mapped through the callback metadata. Here, the
+; first two arguments of the call and the callback callee do not correspond to
+; each other but argument 3-5 of the transitive call site in the caller match
+; arguments 2-4 of the callback callee. Here we should see information and value
+; transfer in both directions.
+; FIXME: The callee -> call site direction is not working yet.
+
+define void @t0_caller(i32* %a) {
+; CHECK:       @t0_caller(i32* [[A:%.*]])
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[B:%.*]] = alloca i32, align 32
+; CHECK-NEXT:    [[C:%.*]] = alloca i32*, align 64
+; CHECK-NEXT:    [[PTR:%.*]] = alloca i32, align 128
+; CHECK-NEXT:    [[TMP0:%.*]] = bitcast i32* [[B]] to i8*
+; CHECK-NEXT:    store i32 42, i32* [[B]], align 32
+; CHECK-NEXT:    store i32* [[B]], i32** [[C]], align 64
+; CHECK-NEXT:    call void (i32*, i32*, void (i32*, i32*, ...)*, ...) @t0_callback_broker(i32* null, i32* nonnull align 128 dereferenceable(4) [[PTR]], void (i32*, i32*, ...)* nonnull bitcast (void (i32*, i32*, i32*, i64, i32**)* @t0_callback_callee to void (i32*, i32*, ...)*), i32* [[A:%.*]], i64 99, i32** nonnull align 64 dereferenceable(8) [[C]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %b = alloca i32, align 32
+  %c = alloca i32*, align 64
+  %ptr = alloca i32, align 128
+  %0 = bitcast i32* %b to i8*
+  store i32 42, i32* %b, align 4
+  store i32* %b, i32** %c, align 8
+  call void (i32*, i32*, void (i32*, i32*, ...)*, ...) @t0_callback_broker(i32* null, i32* %ptr, void (i32*, i32*, ...)* bitcast (void (i32*, i32*, i32*, i64, i32**)* @t0_callback_callee to void (i32*, i32*, ...)*), i32* %a, i64 99, i32** %c)
+  ret void
+}
+
+; Note that the first two arguments are provided by the callback_broker according to the callback in !1 below!
+; The others are annotated with alignment information, amongst others, or even replaced by the constants passed to the call.
+define internal void @t0_callback_callee(i32* %is_not_null, i32* %ptr, i32* %a, i64 %b, i32** %c) {
+; CHECK:       @t0_callback_callee(i32* nocapture writeonly [[IS_NOT_NULL:%.*]], i32* nocapture readonly [[PTR:%.*]], i32* [[A:%.*]], i64 [[B:%.*]], i32** nocapture nonnull readonly align 64 dereferenceable(8) [[C:%.*]])
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PTR_VAL:%.*]] = load i32, i32* [[PTR:%.*]], align 8
+; CHECK-NEXT:    store i32 [[PTR_VAL]], i32* [[IS_NOT_NULL:%.*]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32*, i32** [[C:%.*]], align 64
+; CHECK-NEXT:    tail call void @t0_check(i32* align 256 [[A:%.*]], i64 99, i32* [[TMP0]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %ptr_val = load i32, i32* %ptr, align 8
+  store i32 %ptr_val, i32* %is_not_null
+  %0 = load i32*, i32** %c, align 8
+  tail call void @t0_check(i32* %a, i64 %b, i32* %0)
+  ret void
+}
+
+declare void @t0_check(i32* align 256, i64, i32*)
+
+declare !callback !0 void @t0_callback_broker(i32*, i32*, void (i32*, i32*, ...)*, ...)
+
+!0 = !{!1}
+!1 = !{i64 2, i64 -1, i64 -1, i1 true}