Hi,
FP instructions are only enabled for TARGET_32BIT and TARGET_HARD_FLOAT
but GCC only gives an error when TARGET_HARD_FLOAT is true and -mfpu is
not set. Among other things, it makes some of the cmse tests (eg.
gcc.target/arm/cmse/baseline/softfp.c) fail when targeting
-march=armv8-m.base -mfpu=<something> -mfloat-abi=softfp. This patch
errors out when a Thumb-1 -like target is selected and a FPU is
specified, thus making such tests being skipped.
ChangeLog entries are as follows:
*** gcc/ChangeLog ***
2018-11-28 thomas Preud'homme <thomas.preudho...@linaro.org>
* config/arm/arm.c (arm_options_perform_arch_sanity_checks): Error out
if targeting Thumb-1 with an FPU specified.
*** gcc/testsuite/ChangeLog ***
2018-11-28 thomas Preud'homme <thomas.preudho...@linaro.org>
* gcc.target/arm/thumb1_mfpu-1.c: New testcase.
* gcc.target/arm/thumb1_mfpu-2.c: Likewise.
Testing: No testsuite regression when targeting arm-none-eabi Armv6S-M.
Fails as expected when targeting Armv6-M with an -mfpu or a default FPU.
Succeeds without.
Is this ok for stage3?
Best regards,
Thomas
From 051e38552d7c596873e0303f6ec4272b26d50900 Mon Sep 17 00:00:00 2001
From: Thomas Preud'homme <thomas.preudho...@linaro.org>
Date: Tue, 27 Nov 2018 15:52:38 +0000
Subject: [PATCH] [PATCH, ARM] Error out when -mfpu set and targeting Thumb-1
Hi,
FP instructions are only enabled for TARGET_32BIT and TARGET_HARD_FLOAT
but GCC only gives an error when TARGET_HARD_FLOAT is true and -mfpu is
not set. Among other things, it makes some of the cmse tests (eg.
gcc.target/arm/cmse/baseline/softfp.c) fail when targeting
-march=armv8-m.base -mfpu=<something> -mfloat-abi=softfp. This patch
errors out when a Thumb-1 -like target is selected and a FPU is
specified, thus making such tests being skipped.
ChangeLog entries are as follows:
*** gcc/ChangeLog ***
2018-11-28 thomas Preud'homme <thomas.preudho...@linaro.org>
* config/arm/arm.c (arm_options_perform_arch_sanity_checks): Error out
if targeting Thumb-1 with an FPU specified.
*** gcc/testsuite/ChangeLog ***
2018-11-28 thomas Preud'homme <thomas.preudho...@linaro.org>
* gcc.target/arm/thumb1_mfpu-1.c: New testcase.
* gcc.target/arm/thumb1_mfpu-2.c: Likewise.
Testing: No testsuite regression when targeting arm-none-eabi Armv6S-M.
Fails as expected when targeting Armv6-M with an -mfpu or a default FPU.
Succeeds without.
Is this ok for stage3?
Best regards,
Thomas
---
gcc/config/arm/arm.c | 3 +++
gcc/testsuite/gcc.target/arm/thumb1_mfpu-1.c | 7 +++++++
gcc/testsuite/gcc.target/arm/thumb1_mfpu-2.c | 8 ++++++++
3 files changed, 18 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/arm/thumb1_mfpu-1.c
create mode 100644 gcc/testsuite/gcc.target/arm/thumb1_mfpu-2.c
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 40f0574e32e..1a205123cf5 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3747,6 +3747,9 @@ arm_options_perform_arch_sanity_checks (void)
{
if (arm_abi == ARM_ABI_IWMMXT)
arm_pcs_default = ARM_PCS_AAPCS_IWMMXT;
+ else if (TARGET_THUMB1
+ && bitmap_bit_p (arm_active_target.isa, isa_bit_vfpv2))
+ error ("Thumb-1 does not allow FP instructions");
else if (TARGET_HARD_FLOAT_ABI)
{
arm_pcs_default = ARM_PCS_AAPCS_VFP;
diff --git a/gcc/testsuite/gcc.target/arm/thumb1_mfpu-1.c b/gcc/testsuite/gcc.target/arm/thumb1_mfpu-1.c
new file mode 100644
index 00000000000..5347e63f9b6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/thumb1_mfpu-1.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-skip-if "incompatible float ABI" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=softfp" } } */
+/* { dg-options "-mthumb -mfpu=vfp -mfloat-abi=softfp" } */
+/* { dg-error "Thumb-1 does not allow FP instructions" "" { target *-*-* } 0 } */
+
+int foo;
diff --git a/gcc/testsuite/gcc.target/arm/thumb1_mfpu-2.c b/gcc/testsuite/gcc.target/arm/thumb1_mfpu-2.c
new file mode 100644
index 00000000000..941ed26ed01
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/thumb1_mfpu-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-skip-if "incompatible float ABI" { *-*-* } { "-mfloat-abi=*" } { "-mfloat-abi=softfp" } } */
+/* No need to skip in presence of -mfpu since arm_thumb1_ok will already fail
+ due to Thumb-1 with -mfpu which is tested by thumb1_mfpu-1 testcase. */
+/* { dg-options "-mthumb -mfloat-abi=softfp" } */
+
+int foo;
--
2.19.1
