llvm-6502/test/CodeGen/X86/statepoint-forward.ll
David Blaikie 32b845d223 [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction
See r230786 and r230794 for similar changes to gep and load
respectively.

Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.

When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.

This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.

This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).

No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.

This leaves /only/ the varargs case where the explicit type is required.

Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.

About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.

import fileinput
import sys
import re

pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")

def conv(match, line):
  if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
    return line
  return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]

for line in sys.stdin:
  sys.stdout.write(conv(re.search(pat, line), line))

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235145 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-16 23:24:18 +00:00

108 lines
4.9 KiB
LLVM

; RUN: opt -O3 -S < %s | FileCheck --check-prefix=CHECK-OPT %s
; RUN: llc < %s | FileCheck --check-prefix=CHECK-LLC %s
; These tests are targetted at making sure we don't retain information
; about memory which contains potential gc references across a statepoint.
; They're carefully written to only outlaw forwarding of references.
; Depending on the collector, forwarding non-reference fields or
; constant null references may be perfectly legal. (If unimplemented.)
; The general structure of these tests is:
; - learn a fact about memory (via an assume)
; - cross a statepoint
; - check the same fact about memory (which we no longer know)
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
; If not at a statepoint, we could forward known memory values
; across this call.
declare void @func() readonly
;; Forwarding the value of a pointer load is invalid since it may have
;; changed at the safepoint. Forwarding a non-gc pointer value would
;; be valid, but is not currently implemented.
define i1 @test_load_forward(i32 addrspace(1)* addrspace(1)* %p) gc "statepoint-example" {
entry:
%before = load i32 addrspace(1)*, i32 addrspace(1)* addrspace(1)* %p
%cmp1 = call i1 @f(i32 addrspace(1)* %before)
call void @llvm.assume(i1 %cmp1)
%safepoint_token = tail call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* addrspace(1)* %p)
%pnew = call i32 addrspace(1)* addrspace(1)* @llvm.experimental.gc.relocate.p1p1i32(i32 %safepoint_token, i32 4, i32 4)
%after = load i32 addrspace(1)*, i32 addrspace(1)* addrspace(1)* %pnew
%cmp2 = call i1 @f(i32 addrspace(1)* %after)
ret i1 %cmp2
; CHECK-OPT-LABEL: test_load_forward
; CHECK-OPT: ret i1 %cmp2
; CHECK-LLC-LABEL: test_load_forward
; CHECK-LLC: callq f
}
;; Same as above, but forwarding from a store
define i1 @test_store_forward(i32 addrspace(1)* addrspace(1)* %p,
i32 addrspace(1)* %v) gc "statepoint-example" {
entry:
%cmp1 = call i1 @f(i32 addrspace(1)* %v)
call void @llvm.assume(i1 %cmp1)
store i32 addrspace(1)* %v, i32 addrspace(1)* addrspace(1)* %p
%safepoint_token = tail call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0, i32 addrspace(1)* addrspace(1)* %p)
%pnew = call i32 addrspace(1)* addrspace(1)* @llvm.experimental.gc.relocate.p1p1i32(i32 %safepoint_token, i32 4, i32 4)
%after = load i32 addrspace(1)*, i32 addrspace(1)* addrspace(1)* %pnew
%cmp2 = call i1 @f(i32 addrspace(1)* %after)
ret i1 %cmp2
; CHECK-OPT-LABEL: test_store_forward
; CHECK-OPT: ret i1 %cmp2
; CHECK-LLC-LABEL: test_store_forward
; CHECK-LLC: callq f
}
; A predicate on the pointer which is not simply null, but whose value
; would be known unchanged if the pointer value could be forwarded.
; The implementation of such a function could inspect the integral value
; of the pointer and is thus not safe to reuse after a statepoint.
declare i1 @f(i32 addrspace(1)* %v) readnone
; This is a variant of the test_load_forward test which is intended to
; highlight the fact that a gc pointer can be stored in part of the heap
; that is not itself GC managed. The GC may have an external mechanism
; to know about and update that value at a safepoint. Note that the
; statepoint does not provide the collector with this root.
define i1 @test_load_forward_nongc_heap(i32 addrspace(1)** %p) gc "statepoint-example" {
entry:
%before = load i32 addrspace(1)*, i32 addrspace(1)** %p
%cmp1 = call i1 @f(i32 addrspace(1)* %before)
call void @llvm.assume(i1 %cmp1)
call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0)
%after = load i32 addrspace(1)*, i32 addrspace(1)** %p
%cmp2 = call i1 @f(i32 addrspace(1)* %after)
ret i1 %cmp2
; CHECK-OPT-LABEL: test_load_forward_nongc_heap
; CHECK-OPT: ret i1 %cmp2
; CHECK-LLC-LABEL: test_load_forward_nongc_heap
; CHECK-LLC: callq f
}
;; Same as above, but forwarding from a store
define i1 @test_store_forward_nongc_heap(i32 addrspace(1)** %p,
i32 addrspace(1)* %v) gc "statepoint-example" {
entry:
%cmp1 = call i1 @f(i32 addrspace(1)* %v)
call void @llvm.assume(i1 %cmp1)
store i32 addrspace(1)* %v, i32 addrspace(1)** %p
call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @func, i32 0, i32 0, i32 0)
%after = load i32 addrspace(1)*, i32 addrspace(1)** %p
%cmp2 = call i1 @f(i32 addrspace(1)* %after)
ret i1 %cmp2
; CHECK-OPT-LABEL: test_store_forward_nongc_heap
; CHECK-OPT: ret i1 %cmp2
; CHECK-LLC-LABEL: test_store_forward_nongc_heap
; CHECK-LLC: callq f
}
declare void @llvm.assume(i1)
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)
declare i32 addrspace(1)* addrspace(1)* @llvm.experimental.gc.relocate.p1p1i32(i32, i32, i32) #3