hi,all:
I have try to write some regression tests of llvm,but it is hard for
me.because i have no knowledge about it and few documents about it.
if anyone can give me more documents about it.
thanks
best wishes
changcheng
I am afraid that the document so far you can find about writing
regression test is [1], see how other test cases are written.
Regards,
chenwj
Hi,
thanks for your letter,but i have read it several times,and now i am
confused still.because i do not know how the test work.
for a simple sample:
; RUN: llvm-as < %s | llvm-dis | FileCheck %s
@addr = external global i64
define i64 @add_unsigned(i64 %x, i64 %y) {
; CHECK: %z = add nuw i64 %x, %y
%z = add nuw i64 %x, %y
ret i64 %z
}
1.FileCheck verify the file that llvm-dis output and %s? if i just
want to verify if the file that llvm-dis output contain a string(such
as "abc“),what should i do?
2."; CHECK: %z = add nuw i64 %x, %y" and "%z = add nuw i64 %x, %y" has
the same sentence, why?
so i really want to know more details about how to write a test,but i
can not find more documents out.
thanks
best wishes!
changcheng
Hi Changcheng,
Below is an example took from test/CodeGen/X86/add.ll:
define i32 @test1(i32 inreg %a) nounwind {
%b = add i32 %a, 128
ret i32 %b
; X32: subl $-128, %eax
; X64: subl $-128,
}
1. The first step, you write a function by using LLVM IR.
define i32 @test1(i32 inreg %a) nounwind {
%b = add i32 %a, 128
ret i32 %b
}
This will be left to LLVM toolchain to generate binary code.
2. Then in the test case above, you add comment like,
; X32: subl $-128, %eax
; X64: subl $-128,
so that FileCheck can check the output of LLVM toolchain and what you
expect from it (; comment). O.K., let's go back to your questions,
1.FileCheck verify the file that llvm-dis output and %s? if i just
want to verify if the file that llvm-dis output contain a string(such
as "abc“),what should i do?
%s means the *current* file, so you leave this file (*ll, human
readable LLVM IR) to llvm-as to generate *bc (bitcode, non-reabable
by human), use llvm-dis to get back *ll, then use Filecheck [1] to
compare its stdin (output of llvm-dis) with "; CHECK" line in %s
(i.e., this file). Usually you write what you expect in the test
case file, then let FileCheck to the work. The old way is using
`grep`, but it's not recommanded.
2."; CHECK: %z = add nuw i64 %x, %y" and "%z = add nuw i64 %x, %y" has
the same sentence, why?
Usually you add "; CHECK" in usual case before what you expect from
LLVM toolchain, or as the above example shows it adds "; X32:". This is
one feature of FileCheck, you can specify what line you want to compare
with. Above test/CodeGen/X86/add.ll, you will see:
; RUN: llc < %s -mcpu=generic -march=x86 | FileCheck %s -check-prefix=X32
which means FileCheck now will compare LLVM toolchain's result with lines
with"; X32:" prefix. But in your example, note below commond:
; RUN: llvm-as < %s | llvm-dis | FileCheck %s
It basically assemble LLVM IR first, pipe to llvm-dis to disassemble,
then use FileCheck to check if the content before llvm-as and after
llvm-dis is the same or not (should be the same), That's why you see
; CHECK: %z = add nuw i64 %x, %y
%z = add nuw i64 %x, %y
Regards,
chenwj
hi,chen:
thaks for your explaining,after reading it i have a few problems more.
1.in the sentenses of "X32: subl $-128, %eax" and "; X64: subl
$-128," ,i do not know what means that in detail,these sentences were
writen follow which language rules?
2.i want to write such a test:translate a *.ll(i.e:hello.ll) file to a
*.c file(i.e:hello.c) with llc,then verify if the .c file contian a
certain string(i.e:"abc:). so:
i want to change the old sample to achieve my aim,but i failed.my old
sample like this:
; RUN: llc -march=c < %s | FileCheck %s
; ModuleID = 'hello.c'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@.str = private unnamed_addr constant [12 x i8] c"helloworld\0A\00", align 1
define i32 @main() nounwind uwtable {
entry:
%retval = alloca i32, align 4
store i32 0, i32* %retval
%call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([12
x i8]* @.str, i32 0, i32 0))
ret i32 0
}
declare i32 @printf(i8*, ...)
;
;CHECK: main
;CHECK: printf
can you teach me how to do?
thanks !
changcheng
O n Mon, Aug 27, 2012 at 3:36 PM, ³¯³¥ô (Wei-Ren Chen)
thaks for your explaining,after reading it i have a few problems more.
1.in the sentenses of "X32: subl $-128, %eax" and "; X64: subl
$-128," ,i do not know what means that in detail,these sentences were
writen follow which language rules?
Accroding to what backend developers expect from the backend he wrote
and architecture manual.
2.i want to write such a test:translate a *.ll(i.e:hello.ll) file to a
*.c file(i.e:hello.c) with llc,then verify if the .c file contian a
certain string(i.e:"abc:). so:
i want to change the old sample to achieve my aim,but i failed.my old
sample like this:; RUN: llc -march=c < %s | FileCheck %s
; ModuleID = 'hello.c'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"@.str = private unnamed_addr constant [12 x i8] c"helloworld\0A\00", align 1
define i32 @main() nounwind uwtable {
entry:
%retval = alloca i32, align 4
store i32 0, i32* %retval
%call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([12
x i8]* @.str, i32 0, i32 0))
ret i32 0
}declare i32 @printf(i8*, ...)
;;CHECK: main
;CHECK: printf
The first thing you should know is C backend had been removed from LLVM
since LLVM 3.1 [1], I don't know what you want is doable... Maybe you can
send a new mail or just reply this mail with a different subject like
That will make your intension more explicit. If you're using a *work*
LLVM C backend, have you tried to run `llc -march=c hello.ll` manually
and see what the output is? Are you sure the C backend output is the
same under any enviroment? I mean maybe when you run this test case on
different OS/ISA, then result could be different. And have you tried
the following?
;CHECK: int main()
define i32 @main() nounwind uwtable {
... snip ...
}
Regards,
chenwj
2.i want to write such a test:translate a *.ll(i.e:hello.ll) file to a
*.c file(i.e:hello.c) with llc,then verify if the .c file contian a
certain string(i.e:"abc:). so:
It seems you want to test LLVM C backend, go looking for
llvm-3.0.src/test/CodeGen/CBackend/* (C backend had been
removed from LLVM 3.1).
HTH,
chenwj
i am very surprised that you have known what i want to do,you are capable!
thank you very much.
yours
changcheng
hi,weiren:
i have reading the samples in llvm-3.0.src/test/CodeGen/CBackend/.
and i have two questions,
1. int the file of 2008-02-01-UnalignedLoadStore.ll,have sentences as below:
; RUN: llc < %s -march=c | \
; RUN: grep {struct __attribute__ ((packed, aligned(} | count 4
if " grep {struct __attribute__ ((packed, aligned(}" means to verify
the whole file(llc output) to find out the string of "struct
__attribute__ ((packed, aligned("?
what is the mean of "count 4"?
2.i write a test case with FileCheck like below,but fail:
; RUN: llc -march=c < %s | FileCheck %s
; ModuleID = 'hello.c'
target datalayout =
"e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@.str = private unnamed_addr constant [12 x i8] c"helloworld\0A\00", align 1
define i32 @main() nounwind uwtable {
entry:
%retval = alloca i32, align 4
store i32 0, i32* %retval
%call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([12
x i8]* @.str, i32 0, i32 0))
ret i32 0
}
declare i32 @printf(i8*, ...)
;
;CHECK: main
;CHECK: printf
;CHECK: {define}
i means to check the string of "define" in the file(llc output).i do
not know where is wrong,can you help me?
thanks,
changcheng