llvm-6502/test/Transforms/FunctionAttrs/nocapture.ll
Nick Lewycky b48a18903a Change CaptureTracking to pass a Use* instead of a Value* when a value is
captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.

Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147327 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-28 23:24:21 +00:00

179 lines
4.4 KiB
LLVM

; RUN: opt < %s -functionattrs -S | FileCheck %s
@g = global i32* null ; <i32**> [#uses=1]
; CHECK: define i32* @c1(i32* %q)
define i32* @c1(i32* %q) {
ret i32* %q
}
; CHECK: define void @c2(i32* %q)
define void @c2(i32* %q) {
store i32* %q, i32** @g
ret void
}
; CHECK: define void @c3(i32* %q)
define void @c3(i32* %q) {
call void @c2(i32* %q)
ret void
}
; CHECK: define i1 @c4(i32* %q, i32 %bitno)
define i1 @c4(i32* %q, i32 %bitno) {
%tmp = ptrtoint i32* %q to i32
%tmp2 = lshr i32 %tmp, %bitno
%bit = trunc i32 %tmp2 to i1
br i1 %bit, label %l1, label %l0
l0:
ret i1 0 ; escaping value not caught by def-use chaining.
l1:
ret i1 1 ; escaping value not caught by def-use chaining.
}
@lookup_table = global [2 x i1] [ i1 0, i1 1 ]
; CHECK: define i1 @c5(i32* %q, i32 %bitno)
define i1 @c5(i32* %q, i32 %bitno) {
%tmp = ptrtoint i32* %q to i32
%tmp2 = lshr i32 %tmp, %bitno
%bit = and i32 %tmp2, 1
; subtle escape mechanism follows
%lookup = getelementptr [2 x i1]* @lookup_table, i32 0, i32 %bit
%val = load i1* %lookup
ret i1 %val
}
declare void @throw_if_bit_set(i8*, i8) readonly
; CHECK: define i1 @c6(i8* %q, i8 %bit)
define i1 @c6(i8* %q, i8 %bit) {
invoke void @throw_if_bit_set(i8* %q, i8 %bit)
to label %ret0 unwind label %ret1
ret0:
ret i1 0
ret1:
%exn = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0
cleanup
ret i1 1
}
declare i32 @__gxx_personality_v0(...)
define i1* @lookup_bit(i32* %q, i32 %bitno) readnone nounwind {
%tmp = ptrtoint i32* %q to i32
%tmp2 = lshr i32 %tmp, %bitno
%bit = and i32 %tmp2, 1
%lookup = getelementptr [2 x i1]* @lookup_table, i32 0, i32 %bit
ret i1* %lookup
}
; CHECK: define i1 @c7(i32* %q, i32 %bitno)
define i1 @c7(i32* %q, i32 %bitno) {
%ptr = call i1* @lookup_bit(i32* %q, i32 %bitno)
%val = load i1* %ptr
ret i1 %val
}
; CHECK: define i32 @nc1(i32* %q, i32* nocapture %p, i1 %b)
define i32 @nc1(i32* %q, i32* %p, i1 %b) {
e:
br label %l
l:
%x = phi i32* [ %p, %e ]
%y = phi i32* [ %q, %e ]
%tmp = bitcast i32* %x to i32* ; <i32*> [#uses=2]
%tmp2 = select i1 %b, i32* %tmp, i32* %y
%val = load i32* %tmp2 ; <i32> [#uses=1]
store i32 0, i32* %tmp
store i32* %y, i32** @g
ret i32 %val
}
; CHECK: define void @nc2(i32* nocapture %p, i32* %q)
define void @nc2(i32* %p, i32* %q) {
%1 = call i32 @nc1(i32* %q, i32* %p, i1 0) ; <i32> [#uses=0]
ret void
}
; CHECK: define void @nc3(void ()* nocapture %p)
define void @nc3(void ()* %p) {
call void %p()
ret void
}
declare void @external(i8*) readonly nounwind
; CHECK: define void @nc4(i8* nocapture %p)
define void @nc4(i8* %p) {
call void @external(i8* %p)
ret void
}
; CHECK: define void @nc5(void (i8*)* nocapture %f, i8* nocapture %p)
define void @nc5(void (i8*)* %f, i8* %p) {
call void %f(i8* %p) readonly nounwind
call void %f(i8* nocapture %p)
ret void
}
; CHECK: define void @test1_1(i8* nocapture %x1_1, i8* %y1_1)
define void @test1_1(i8* %x1_1, i8* %y1_1) {
call i8* @test1_2(i8* %x1_1, i8* %y1_1)
store i32* null, i32** @g
ret void
}
; CHECK: define i8* @test1_2(i8* nocapture %x1_2, i8* %y1_2)
define i8* @test1_2(i8* %x1_2, i8* %y1_2) {
call void @test1_1(i8* %x1_2, i8* %y1_2)
store i32* null, i32** @g
ret i8* %y1_2
}
; CHECK: define void @test2(i8* nocapture %x2)
define void @test2(i8* %x2) {
call void @test2(i8* %x2)
store i32* null, i32** @g
ret void
}
; CHECK: define void @test3(i8* nocapture %x3, i8* nocapture %y3, i8* nocapture %z3)
define void @test3(i8* %x3, i8* %y3, i8* %z3) {
call void @test3(i8* %z3, i8* %y3, i8* %x3)
store i32* null, i32** @g
ret void
}
; CHECK: define void @test4_1(i8* %x4_1)
define void @test4_1(i8* %x4_1) {
call i8* @test4_2(i8* %x4_1, i8* %x4_1, i8* %x4_1)
store i32* null, i32** @g
ret void
}
; CHECK: define i8* @test4_2(i8* nocapture %x4_2, i8* %y4_2, i8* nocapture %z4_2)
define i8* @test4_2(i8* %x4_2, i8* %y4_2, i8* %z4_2) {
call void @test4_1(i8* null)
store i32* null, i32** @g
ret i8* %y4_2
}
declare i8* @test5_1(i8* %x5_1)
; CHECK: define void @test5_2(i8* %x5_2)
define void @test5_2(i8* %x5_2) {
call i8* @test5_1(i8* %x5_2)
store i32* null, i32** @g
ret void
}
declare void @test6_1(i8* %x6_1, i8* nocapture %y6_1, ...)
; CHECK: define void @test6_2(i8* %x6_2, i8* nocapture %y6_2, i8* %z6_2)
define void @test6_2(i8* %x6_2, i8* %y6_2, i8* %z6_2) {
call void (i8*, i8*, ...)* @test6_1(i8* %x6_2, i8* %y6_2, i8* %z6_2)
store i32* null, i32** @g
ret void
}