James Greenhalgh writes:
> On Thu, Aug 06, 2015 at 05:16:33PM +0100, Jiong Wang wrote:
>
> Hi Jiong,
>
> The new testcases introduced in this and the related patch are failing
> for me on aarch64-none-elf:
>
> aarch64-none-elf
>
> NA->FAIL: gcc.target/aarch64/noplt_1.c scan-assembler
> NA->FAIL: gcc.target/aarch64/noplt_2.c scan-assembler-times
> NA->FAIL: gcc.target/aarch64/noplt_3.c scan-assembler-times
>
> For this invocation:
>
> .../build/obj/gcc2/gcc/xgcc -B.../build/obj/gcc2/gcc/
> .../src/gcc/testsuite/gcc.target/aarch64/noplt_1.c
> -fno-diagnostics-show-caret -fdiagnostics-color=never -O2 -fno-plt -fpic -S
> -mcmodel=small -o noplt_1.s
>
> I get this code generation for the small memory model:
>
> foo:
> stp x29, x30, [sp, -32]!
> adrp x1, _GLOBAL_OFFSET_TABLE_
> add x29, sp, 0
> str x19, [sp, 16]
> mov w19, w0
> ldr x0, [x1, #:gotpage_lo15:bar]
> blr x0
> ldr w0, [x0, w19, sxtw 2]
> ldr x19, [sp, 16]
> ldp x29, x30, [sp], 32
> ret
> .size foo, .-foo
>
> Which uses a different relocation.
>
> Did you intend for these tests to be run with -fPIC -fno-plt rather than
> -fpic -fno-plt, or does this indicate a bug?
>
> Thanks,
> James
Thanks for noticed this.
As it's -fpic in dg-option, so they are supposed to work under -fpic,
while I was checking the instruction sequences for -fPIC which is wrong.
It's passed on my local machine because I was doing cross-check and
there is no cross binutils installed, I only built cc1, then run the
check. After double check I found actually all those scan-assemble
test have not been triggered, because looks like the dejagnu was using
local x86 assembler to do some prerequite check, then found -EL not
supported, then those prerequite check returns false.
Even worse, as -fpic for AArch64 will fall back to -fPIC if the
installed aarch64 binutils don't support recently added relocation
types for -fpic, so even I have wrote correct instruction sequences in
this testcase, it will fail on those environment where old binutils
installed, and... even new binutils installed, they may still fail if
the user pre-configure gcc with -mabi=ilp32, as for ILP32, the
relocation modifer for small code small for -fPIC is gotpage_14
instead of gotpage_15 for LP64.
Unfortunally, after all above considered, these testcases still fail
if the user force -mcmodel=tiny to the compilation options, because
those dejagnu target effective check will not know those extra options
user added.
After second think, I found my previous checking logic is not
good. It's better we check the final branch type instead of be
bothered by those relocation modifiers.
Because the fundanmental changes -fno-plt bring us is it turn direct
branch into indirect branch, then turn "bl/b" into "blr/br", while
those GOT reloated modifers are just for preparing the branch
destination register.
Patch pass -fpic/-fPIC/binutils-without-fpic/binutils-with-fpic/ilp32.
Should be OK now.
Commited as obivious.
Thanks.
2015-08-07 Jiong Wang <[email protected]>
gcc/testsuite/
* gcc.target/aarch64/noplt_1.c: Check branch type instead of
relocation modifers.
* gcc.target/aarch64/noplt_2.c: Likewise.
* gcc.target/aarch64/noplt_3.c: Likewise.
--
Regards,
Jiong
diff --git a/gcc/testsuite/gcc.target/aarch64/noplt_1.c b/gcc/testsuite/gcc.target/aarch64/noplt_1.c
index 4e9bb62..731fcae 100644
--- a/gcc/testsuite/gcc.target/aarch64/noplt_1.c
+++ b/gcc/testsuite/gcc.target/aarch64/noplt_1.c
@@ -11,5 +11,5 @@ foo (int a)
return b[a];
}
-/* { dg-final { scan-assembler "#:got:" { target { aarch64_tiny || aarch64_small } } } } */
-/* { dg-final { scan-assembler "#:got_lo12:" { target aarch64_small } } } */
+/* { dg-final { scan-assembler "blr" } } */
+/* { dg-final { scan-assembler-not "bl\t" } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/noplt_2.c b/gcc/testsuite/gcc.target/aarch64/noplt_2.c
index 718999b..3be94aa 100644
--- a/gcc/testsuite/gcc.target/aarch64/noplt_2.c
+++ b/gcc/testsuite/gcc.target/aarch64/noplt_2.c
@@ -14,5 +14,5 @@ foo (int a)
return b0[a] + b1[a];
}
-/* { dg-final { scan-assembler-times "#:got:" 1 { target { aarch64_tiny || aarch64_small } } } } */
-/* { dg-final { scan-assembler-times "#:got_lo12:" 1 { target aarch64_small } } } */
+/* { dg-final { scan-assembler-times "blr" 1 } } */
+/* { dg-final { scan-assembler-times "bl\t" 1 } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/noplt_3.c b/gcc/testsuite/gcc.target/aarch64/noplt_3.c
index c1993b6..ef6e65d 100644
--- a/gcc/testsuite/gcc.target/aarch64/noplt_3.c
+++ b/gcc/testsuite/gcc.target/aarch64/noplt_3.c
@@ -16,5 +16,5 @@ cal_novalue (int a)
dec (a);
}
-/* { dg-final { scan-assembler-times "#:got:" 2 { target { aarch64_tiny || aarch64_small } } } } */
-/* { dg-final { scan-assembler-times "#:got_lo12:" 2 { target aarch64_small } } } */
+/* { dg-final { scan-assembler-times "br" 2 } } */
+/* { dg-final { scan-assembler-not "b\t" } } */
