| Message ID | 20231113142658.69039-3-rearnsha@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | arm: testsuite: clean up some architecture-specific tests | expand |
Hi Richard, On Mon, 13 Nov 2023 at 15:27, Richard Earnshaw <rearnsha@arm.com> wrote: > > > Add an arm-specific test to check_effective_target_hard_float for > Arm to handle cases where we only have single-precision FP in hardware. > > gcc/testsuite: > > * lib/target-supports.exp (check_effective_target_hard_float): Add > arm-specific test. > --- > gcc/testsuite/lib/target-supports.exp | 11 +++++++++++ > 1 file changed, 11 insertions(+) > Our CI has detected a problem when testing this patch for cortex-m33: with -mthumb/-march=armv8-m.main+dsp+fp/-mtune=cortex-m33/-mfloat-abi=hard/-mfpu=auto and GCC configured with --disable-multilib --with-mode=thumb --with-cpu=cortex-m33 --with-float=hard FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O0 execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O1 execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O2 execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O2 -flto -fno-use-linker-plugin -flto-partition=none execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -O3 -g execution test FAIL: gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c -Os execution test We use qemu for testing. Do these tests pass in your configuration? Thanks, Christophe
On 20/11/2023 10:41, Christophe Lyon wrote: > Hi Richard, > > > On Mon, 13 Nov 2023 at 15:27, Richard Earnshaw <rearnsha@arm.com> wrote: >> >> >> Add an arm-specific test to check_effective_target_hard_float for >> Arm to handle cases where we only have single-precision FP in hardware. >> >> gcc/testsuite: >> >> * lib/target-supports.exp (check_effective_target_hard_float): Add >> arm-specific test. >> --- >> gcc/testsuite/lib/target-supports.exp | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> > > Our CI has detected a problem when testing this patch for cortex-m33: > with > -mthumb/-march=armv8-m.main+dsp+fp/-mtune=cortex-m33/-mfloat-abi=hard/-mfpu=auto > and GCC configured with --disable-multilib --with-mode=thumb > --with-cpu=cortex-m33 --with-float=hard > > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O0 execution test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O1 execution test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O2 execution test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O2 -flto -fno-use-linker-plugin -flto-partition=none execution > test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects execution test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -O3 -g execution test > FAIL: > gcc:gcc.dg/torture/dg-torture.exp=gcc.dg/torture/fp-double-convert-float-1.c > -Os execution test > I think this technically is a real bug in the port. This test changes the rounding modes, but cortex-m33 only has a single-precision FP unit, so single-precision is handled in HW, while double-precision is handled in SW. The soft-float functions don't support changing the rounding mode, and certainly not through fesetround(), so we don't get the expected results. I think the test would always have failed, but we didn't run it in the past as the default test for HW fp only checked for double precision HW. Fixing the real problem is not trivial though, especially in a mixed hard/soft environment. > We use qemu for testing. Do these tests pass in your configuration? > > Thanks, > > Christophe R.
diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index d414cddf4dc..ee173b9fb6b 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -1420,6 +1420,17 @@ proc check_effective_target_mpaired_single { args } { # Return true if the target has access to FPU instructions. proc check_effective_target_hard_float { } { + # This should work on cores that only have single-precision, + # and should also correctly handle legacy cores that had thumb1 and + # lacked FP support for that, but had it in Arm state. + if { [istarget arm*-*-*] } { + return [check_no_compiler_messages hard_float assembly { + #if __ARM_FP == 0 + #error __arm_soft_float + #endif + }] + } + if { [istarget loongarch*-*-*] } { return [check_no_compiler_messages hard_float assembly { #if (defined __loongarch_soft_float)