llvm-6502/test/Transforms/RewriteStatepointsForGC/base-pointers.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

101 lines
4.6 KiB
LLVM

; RUN: opt %s -rewrite-statepoints-for-gc -S 2>&1 | FileCheck %s
declare i64 addrspace(1)* @generate_obj()
declare void @use_obj(i64 addrspace(1)*)
; The rewriting needs to make %obj loop variant by inserting a phi
; of the original value and it's relocation.
define void @def_use_safepoint() gc "statepoint-example" {
; CHECK-LABEL: def_use_safepoint
entry:
%obj = call i64 addrspace(1)* @generate_obj()
br label %loop
loop:
; CHECK: phi i64 addrspace(1)*
; CHECK-DAG: [ %obj.relocated, %loop ]
; CHECK-DAG: [ %obj, %entry ]
call void @use_obj(i64 addrspace(1)* %obj)
%safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @do_safepoint, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %loop
}
declare void @do_safepoint()
declare void @parse_point(i64 addrspace(1)*)
define i64 addrspace(1)* @test1(i32 %caller, i8 addrspace(1)* %a, i8 addrspace(1)* %b, i32 %unknown) gc "statepoint-example" {
; CHECK-LABEL: test1
entry:
br i1 undef, label %left, label %right
left:
%a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)*
; CHECK: left:
; CHECK-NEXT: %a.cast = bitcast i8 addrspace(1)* %a to i64 addrspace(1)*
; CHECK-NEXT: [[CAST_L:%.*]] = bitcast i8 addrspace(1)* %a to i64 addrspace(1)*
; Our safepoint placement pass calls removeUnreachableBlocks, which does a bunch
; of simplifications to branch instructions. This bug is visible only when
; there are multiple branches into the same block from the same predecessor, and
; the following ceremony is to make that artefact survive a call to
; removeUnreachableBlocks. As an example, "br i1 undef, label %merge, label %merge"
; will get simplified to "br label %merge" by removeUnreachableBlocks.
switch i32 %unknown, label %right [ i32 0, label %merge
i32 1, label %merge
i32 5, label %merge
i32 3, label %right ]
right:
%b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)*
br label %merge
; CHECK: right:
; CHECK-NEXT: %b.cast = bitcast i8 addrspace(1)* %b to i64 addrspace(1)*
; CHECK-NEXT: [[CAST_R:%.*]] = bitcast i8 addrspace(1)* %b to i64 addrspace(1)*
merge:
; CHECK: merge:
; CHECK-NEXT: %base_phi = phi i64 addrspace(1)* [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_L]], %left ], [ [[CAST_R]], %right ], !is_base_value !0
%value = phi i64 addrspace(1)* [ %a.cast, %left], [ %a.cast, %left], [ %a.cast, %left], [ %b.cast, %right]
%safepoint_token = call i32 (void (i64 addrspace(1)*)*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(void (i64 addrspace(1)*)* @parse_point, i32 1, i32 0, i64 addrspace(1)* %value, i32 5, i32 0, i32 0, i32 0, i32 0, i32 0)
ret i64 addrspace(1)* %value
}
;; The purpose of this test is to ensure that when two live values share a
;; base defining value with inherent conflicts, we end up with a *single*
;; base phi/select per such node. This is testing an optimization, not a
;; fundemental correctness criteria
define void @test2(i1 %cnd, i64 addrspace(1)* %base_obj, i64 addrspace(1)* %base_arg2) gc "statepoint-example" {
; CHECK-LABEL: @test2
entry:
%obj = getelementptr i64, i64 addrspace(1)* %base_obj, i32 1
br label %loop
loop: ; preds = %loop, %entry
; CHECK-LABEL: loop
; CHECK: %base_phi = phi i64 addrspace(1)*
; CHECK-DAG: [ %base_obj, %entry ]
; Given the two selects are equivelent, so are their base phis - ideally,
; we'd have commoned these, but that's a missed optimization, not correctness.
; CHECK-DAG: [ [[DISCARD:%base_select.*.relocated]], %loop ]
; CHECK-NOT: base_phi2
; CHECK: next = select
; CHECK: base_select
; CHECK: extra2 = select
; CHECK: base_select
; CHECK: statepoint
;; Both 'next' and 'extra2' are live across the backedge safepoint...
%current = phi i64 addrspace(1)* [ %obj, %entry ], [ %next, %loop ]
%extra = phi i64 addrspace(1)* [ %obj, %entry ], [ %extra2, %loop ]
%nexta = getelementptr i64, i64 addrspace(1)* %current, i32 1
%next = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2
%extra2 = select i1 %cnd, i64 addrspace(1)* %nexta, i64 addrspace(1)* %base_arg2
%safepoint_token = call i32 (void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()* @foo, i32 0, i32 0, i32 5, i32 0, i32 -1, i32 0, i32 0, i32 0)
br label %loop
}
declare void @foo()
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(void ()*, i32, i32, ...)
declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidp1i64f(void (i64 addrspace(1)*)*, i32, i32, ...)