On 01/04/2021 18:35, Richard Earnshaw wrote:
>
>
> On 01/04/2021 17:11, Alex Coplan via Gcc-patches wrote:
> > Hi all,
> >
> > This patch fixes PR99748 which shows us trying to pass the argument to
> > __aeabi_f2iz in the VFP register s0 when the library function is
> > expecting to use the GPR r0. It also fixes the __aeabi_f2uiz case which
> > was broken in the same way.
> >
> > For the testcase in the PR, here is the code we generate before the
> > patch (with -mfloat-abi=hard -march=armv8.1-m.main+mve -O0):
> >
> > main:
> > push {r7, lr}
> > sub sp, sp, #8
> > add r7, sp, #0
> > mov r3, #1065353216
> > str r3, [r7, #4] @ float
> > vldr.32 s0, [r7, #4]
> > bl __aeabi_f2iz
> > mov r3, r0
> > cmp r3, #1
> > [...]
> >
> > This becomes:
> >
> > main:
> > push {r7, lr}
> > sub sp, sp, #8
> > add r7, sp, #0
> > mov r3, #1065353216
> > str r3, [r7, #4] @ float
> > ldr r0, [r7, #4] @ float
> > bl __aeabi_f2iz
> > mov r3, r0
> > cmp r3, #1
> > [...]
> >
> > after the patch. We see a similar change for the same testcase with a
> > cast to unsigned instead of int.
> >
> > Testing:
> > * Bootstrapped and regtested on arm-linux-gnueabihf, no regressions.
> > * Regtested an arm-eabi cross configured with --with-float=hard
> > --with-arch=armv8.1-m.main+mve. This shows that the patch fixes the
> > following execution failures:
> >
> > FAIL->PASS: gcc.c-torture/execute/20000605-1.c -O0 execution test
> > FAIL->PASS: gcc.c-torture/execute/conversion.c -O0 execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -O0 execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -O1 execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -O2 execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -O2 -flto
> > -fno-use-linker-plugin -flto-partition=none execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -O3 -g execution test
> > FAIL->PASS: gcc.c-torture/execute/float-floor.c -Os execution test
> > FAIL->PASS: gcc.c-torture/execute/gofast.c -O0 execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O0 execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O1 execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O2 execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O2 -flto
> > -fno-use-linker-plugin -flto-partition=none execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O2 -flto
> > -fuse-linker-plugin -fno-fat-lto-objects execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -O3 -g execution test
> > FAIL->PASS: gcc.dg/torture/float32-basic.c -Os execution test
> >
> > OK for trunk?
> >
> > Thanks,
> > Alex
> >
> > gcc/ChangeLog:
> >
> > * config/arm/arm.c (arm_libcall_uses_aapcs_base): Also use base
> > PCS for [su]fix_optab.
> >
>
> OK.
>
> As a wrong code bug we should probably be looking to backport this if needed
> (though it's likely too late now for 10.3).
Testing shows the patch fixes the issue on the 10 branch. Bootstrapped
on arm-linux-gnueabihf and regtested an MVE cross: no issues.
Cherry-picked as
r10-9755-g283367662c25057fd7c9c98257cca858f85b75fc.
>
> R.
Thanks,
Alex
