135 lines
5.7 KiB
LLVM
135 lines
5.7 KiB
LLVM
; The CGSCC pass manager includes an SCC iteration utility that tracks indirect
|
|
; calls that are turned into direct calls (devirtualization) and re-visits the
|
|
; SCC to expose those calls to the SCC-based IPO passes. We trigger
|
|
; devirtualization here with GVN which forwards a store through a load and to
|
|
; an indirect call.
|
|
;
|
|
; RUN: opt -aa-pipeline=basic-aa -passes='cgscc(function-attrs,function(gvn,instcombine))' -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=BEFORE
|
|
; RUN: opt -aa-pipeline=basic-aa -passes='cgscc(devirt<1>(function-attrs,function(gvn,instcombine)))' -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=AFTER --check-prefix=AFTER1
|
|
; RUN: opt -aa-pipeline=basic-aa -passes='cgscc(devirt<2>(function-attrs,function(gvn,instcombine)))' -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=AFTER --check-prefix=AFTER2
|
|
;
|
|
; RUN: not --crash opt -abort-on-max-devirt-iterations-reached -aa-pipeline=basic-aa -passes='cgscc(devirt<1>(function-attrs,function(gvn,instcombine)))' -S < %s
|
|
; RUN: opt -abort-on-max-devirt-iterations-reached -aa-pipeline=basic-aa -passes='cgscc(devirt<2>(function-attrs,function(gvn,instcombine)))' -S < %s
|
|
;
|
|
; We also verify that the real O2 pipeline catches these cases.
|
|
; RUN: opt -aa-pipeline=basic-aa -passes='default<O2>' -S < %s | FileCheck %s --check-prefix=CHECK --check-prefix=AFTER --check-prefix=AFTER2
|
|
|
|
declare void @readnone() readnone
|
|
; CHECK: Function Attrs: readnone
|
|
; CHECK-NEXT: declare void @readnone()
|
|
|
|
declare void @unknown()
|
|
; CHECK-NOT: Function Attrs
|
|
; CHECK-LABEL: declare void @unknown(){{ *$}}
|
|
|
|
; The @test1 function checks that when we refine an indirect call to a direct
|
|
; call we revisit the SCC passes to reflect the more precise information. This
|
|
; is the basic functionality.
|
|
|
|
define void @test1() {
|
|
; BEFORE-NOT: Function Attrs
|
|
; AFTER: Function Attrs: readnone
|
|
; CHECK-LABEL: define void @test1()
|
|
entry:
|
|
%fptr = alloca void ()*
|
|
store void ()* @readnone, void ()** %fptr
|
|
%f = load void ()*, void ()** %fptr
|
|
call void %f()
|
|
ret void
|
|
}
|
|
|
|
; The @test2_* functions check that when we need multiple (in this case 2)
|
|
; repetitions to compute some state that is incrementally exposed with each
|
|
; one, the limit on repetitions is enforced. So we make progress with
|
|
; one repetition but not as much as with three.
|
|
;
|
|
; This is somewhat awkward to test because we have to contrive to have a state
|
|
; repetition triggered and observed with very few passes. The technique here
|
|
; is to have one indirect call that can only be resolved when the entire SCC is
|
|
; deduced as readonly, and mark that indirect call at the call site as readonly
|
|
; to make that possible. This forces us to first deduce readonly, then
|
|
; devirtualize again, and then deduce readnone.
|
|
|
|
declare void @readnone_with_arg(void ()**) readnone
|
|
; CHECK: Function Attrs: readnone
|
|
; CHECK-LABEL: declare void @readnone_with_arg(void ()**)
|
|
|
|
define void @test2_a(void ()** %ignore) {
|
|
; BEFORE-NOT: Function Attrs
|
|
; AFTER1: Function Attrs: readonly
|
|
; AFTER2: Function Attrs: readnone
|
|
; BEFORE: define void @test2_a(void ()** %ignore)
|
|
; AFTER: define void @test2_a(void ()** readnone %ignore)
|
|
entry:
|
|
%f1ptr = alloca void (void ()**)*
|
|
store void (void ()**)* @readnone_with_arg, void (void ()**)** %f1ptr
|
|
%f1 = load void (void ()**)*, void (void ()**)** %f1ptr
|
|
; This indirect call is the first to be resolved, allowing us to deduce
|
|
; readonly but not (yet) readnone.
|
|
call void %f1(void ()** %ignore)
|
|
; CHECK: call void @readnone_with_arg(void ()** %ignore)
|
|
|
|
; Bogus call to test2_b to make this a cycle.
|
|
call void @test2_b()
|
|
|
|
ret void
|
|
}
|
|
|
|
define void @test2_b() {
|
|
; BEFORE-NOT: Function Attrs
|
|
; AFTER1: Function Attrs: readonly
|
|
; AFTER2: Function Attrs: readnone
|
|
; CHECK-LABEL: define void @test2_b()
|
|
entry:
|
|
%f2ptr = alloca void ()*
|
|
store void ()* @readnone, void ()** %f2ptr
|
|
; Call the other function here to prevent forwarding until the SCC has had
|
|
; function attrs deduced.
|
|
call void @test2_a(void ()** %f2ptr)
|
|
|
|
%f2 = load void ()*, void ()** %f2ptr
|
|
; This is the second indirect call to be resolved, and can only be resolved
|
|
; after we deduce 'readonly' for the rest of the SCC. Once it is
|
|
; devirtualized, we can deduce readnone for the SCC.
|
|
call void %f2() readonly
|
|
; BEFORE: call void %f2()
|
|
; AFTER: call void @readnone()
|
|
|
|
ret void
|
|
}
|
|
|
|
declare i8* @memcpy(i8*, i8*, i64)
|
|
; CHECK-LABEL: i8* @memcpy(
|
|
|
|
; The @test3 function checks that when we refine an indirect call to an
|
|
; intrinsic we still revisit the SCC pass. This also covers cases where the
|
|
; value handle itself doesn't persist due to the nature of how instcombine
|
|
; creates the memcpy intrinsic call, and we rely on the count of indirect calls
|
|
; decreasing and the count of direct calls increasing.
|
|
; Adding 'noinline' attribute to force attributes for improved matching.
|
|
define void @test3(i8* %src, i8* %dest, i64 %size) noinline {
|
|
; CHECK: Function Attrs
|
|
; CHECK-NOT: read
|
|
; CHECK-SAME: noinline
|
|
; BEFORE-LABEL: define void @test3(i8* %src, i8* %dest, i64 %size)
|
|
; AFTER-LABEL: define void @test3(i8* nocapture readonly %src, i8* nocapture %dest, i64 %size)
|
|
%fptr = alloca i8* (i8*, i8*, i64)*
|
|
store i8* (i8*, i8*, i64)* @memcpy, i8* (i8*, i8*, i64)** %fptr
|
|
%f = load i8* (i8*, i8*, i64)*, i8* (i8*, i8*, i64)** %fptr
|
|
call i8* %f(i8* %dest, i8* %src, i64 %size)
|
|
; CHECK: call void @llvm.memcpy
|
|
ret void
|
|
}
|
|
|
|
; A boring function that just keeps our declarations around.
|
|
define void @keep(i8** %sink) {
|
|
; CHECK-NOT: Function Attrs
|
|
; CHECK-LABEL: define void @keep(
|
|
entry:
|
|
store volatile i8* bitcast (void ()* @readnone to i8*), i8** %sink
|
|
store volatile i8* bitcast (void ()* @unknown to i8*), i8** %sink
|
|
store volatile i8* bitcast (i8* (i8*, i8*, i64)* @memcpy to i8*), i8** %sink
|
|
call void @unknown()
|
|
ret void
|
|
}
|