llvm-6502/test/Transforms/GVN/invariant-load.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

120 lines
2.9 KiB
LLVM

; Test if the !invariant.load metadata is maintained by GVN.
; RUN: opt -basicaa -gvn -S < %s | FileCheck %s
define i32 @test1(i32* nocapture %p, i8* nocapture %q) {
; CHECK-LABEL: test1
; CHECK: %x = load i32, i32* %p, align 4, !invariant.load !0
; CHECK-NOT: %y = load
entry:
%x = load i32, i32* %p, align 4, !invariant.load !0
%conv = trunc i32 %x to i8
store i8 %conv, i8* %q, align 1
%y = load i32, i32* %p, align 4, !invariant.load !0
%add = add i32 %y, 1
ret i32 %add
}
define i32 @test2(i32* nocapture %p, i8* nocapture %q) {
; CHECK-LABEL: test2
; CHECK-NOT: !invariant.load
; CHECK-NOT: %y = load
entry:
%x = load i32, i32* %p, align 4
%conv = trunc i32 %x to i8
store i8 %conv, i8* %q, align 1
%y = load i32, i32* %p, align 4, !invariant.load !0
%add = add i32 %y, 1
ret i32 %add
}
; With the invariant.load metadata, what would otherwise
; be a case for PRE becomes a full redundancy.
define i32 @test3(i1 %cnd, i32* %p, i32* %q) {
; CHECK-LABEL: test3
; CHECK-NOT: load
entry:
%v1 = load i32, i32* %p
br i1 %cnd, label %bb1, label %bb2
bb1:
store i32 5, i32* %q
br label %bb2
bb2:
%v2 = load i32, i32* %p, !invariant.load !0
%res = sub i32 %v1, %v2
ret i32 %res
}
; This test is here to document a case which doesn't optimize
; as well as it could.
define i32 @test4(i1 %cnd, i32* %p, i32* %q) {
; CHECK-LABEL: test4
; %v2 is redundant, but GVN currently doesn't catch that
entry:
%v1 = load i32, i32* %p, !invariant.load !0
br i1 %cnd, label %bb1, label %bb2
bb1:
store i32 5, i32* %q
br label %bb2
bb2:
%v2 = load i32, i32* %p
%res = sub i32 %v1, %v2
ret i32 %res
}
; Checks that we return the mustalias store as a def
; so that it contributes to value forwarding. Note
; that we could and should remove the store too.
define i32 @test5(i1 %cnd, i32* %p) {
; CHECK-LABEL: test5
; CHECK-LABEL: entry:
; CHECK-NEXT: store i32 5, i32* %p
; CHECK-NEXT: ret i32 5
entry:
%v1 = load i32, i32* %p, !invariant.load !0
store i32 5, i32* %p ;; must alias store, want to exploit
%v2 = load i32, i32* %p, !invariant.load !0
ret i32 %v2
}
declare void @foo()
; Clobbering (mayalias) stores, even in function calls, can be ignored
define i32 @test6(i1 %cnd, i32* %p) {
; CHECK-LABEL: test6
; CHECK-LABEL: entry:
; CHECK-NEXT: @foo
; CHECK-NEXT: ret i32 0
entry:
%v1 = load i32, i32* %p, !invariant.load !0
call void @foo()
%v2 = load i32, i32* %p, !invariant.load !0
%res = sub i32 %v1, %v2
ret i32 %res
}
declare noalias i32* @bar(...)
; Same as previous, but a function with a noalias result (since they're handled
; differently in MDA)
define i32 @test7(i1 %cnd, i32* %p) {
; CHECK-LABEL: test7
; CHECK-LABEL: entry:
; CHECK-NEXT: @bar
; CHECK-NEXT: ret i32 0
entry:
%v1 = load i32, i32* %p, !invariant.load !0
call i32* (...) @bar(i32* %p)
%v2 = load i32, i32* %p, !invariant.load !0
%res = sub i32 %v1, %v2
ret i32 %res
}
!0 = !{ }