Merge v7-M and v7E-M library variants (#482)

The only differece between v7-M and v7E-M is the DSP extension, which is
not useful for the C/C++ libraries, so we can simplify things by just
having v7-M builds. This fills in a gap of (v7-M, fpv4-sp-d16,
hard-float), which we did not previously have a valid library for.

CMakeLists.txt

@@ -1654,25 +1654,9 @@ add_library_variants_for_cpu(
 )
 add_library_variants_for_cpu(
     armv7m
-    SUFFIX soft_nofp
-    COMPILE_FLAGS "-mfloat-abi=soft -march=armv7m -mfpu=none"
-    MULTILIB_FLAGS "--target=thumbv7m-unknown-none-eabi -mfpu=none"
-    PICOLIBC_BUILD_TYPE "minsize"
-    QEMU_MACHINE "mps2-an385"
-    QEMU_CPU "cortex-m3"
-    BOOT_FLASH_ADDRESS 0x00000000
-    BOOT_FLASH_SIZE 0x1000
-    FLASH_ADDRESS 0x21000000
-    FLASH_SIZE 0x600000
-    RAM_ADDRESS 0x21600000
-    RAM_SIZE 0xa00000
-    STACK_SIZE 4K
-)
-add_library_variants_for_cpu(
-    armv7em
     SUFFIX hard_fpv4_sp_d16
-    COMPILE_FLAGS "-mfloat-abi=hard -march=armv7em -mfpu=fpv4-sp-d16"
-    MULTILIB_FLAGS "--target=thumbv7em-unknown-none-eabihf -mfpu=fpv4-sp-d16"
+    COMPILE_FLAGS "-mfloat-abi=hard -march=armv7m -mfpu=fpv4-sp-d16"
+    MULTILIB_FLAGS "--target=thumbv7m-unknown-none-eabihf -mfpu=fpv4-sp-d16"
     PICOLIBC_BUILD_TYPE "minsize"
     QEMU_MACHINE "mps2-an386"
     QEMU_CPU "cortex-m4"
@@ -1685,10 +1669,10 @@ add_library_variants_for_cpu(
     STACK_SIZE 4K
 )
 add_library_variants_for_cpu(
-    armv7em
+    armv7m
     SUFFIX hard_fpv5_d16
-    COMPILE_FLAGS "-mfloat-abi=hard -march=armv7em -mfpu=fpv5-d16"
-    MULTILIB_FLAGS "--target=thumbv7em-unknown-none-eabihf -mfpu=fpv5-d16"
+    COMPILE_FLAGS "-mfloat-abi=hard -march=armv7m -mfpu=fpv5-d16"
+    MULTILIB_FLAGS "--target=thumbv7m-unknown-none-eabihf -mfpu=fpv5-d16"
     PICOLIBC_BUILD_TYPE "minsize"
     QEMU_MACHINE "mps2-an500"
     QEMU_CPU "cortex-m7"
@@ -1705,12 +1689,12 @@ add_library_variants_for_cpu(
 # no-fpu variant to win, it has to be in multilab.yaml after all other
 # fpu variants. The order of variants in multilab.yaml depends on the order
 # of the add_library_variant calls. So the add_library_variant that adds
-# the soft_nofp for armv7em is placed after all other armv7em variants.
+# the soft_nofp for armv7m is placed after all other armv7m variants.
 add_library_variants_for_cpu(
-    armv7em
+    armv7m
     SUFFIX soft_nofp
-    COMPILE_FLAGS "-mfloat-abi=soft -march=armv7em -mfpu=none"
-    MULTILIB_FLAGS "--target=thumbv7em-unknown-none-eabi -mfpu=none"
+    COMPILE_FLAGS "-mfloat-abi=soft -march=armv7m -mfpu=none"
+    MULTILIB_FLAGS "--target=thumbv7m-unknown-none-eabi -mfpu=none"
     PICOLIBC_BUILD_TYPE "minsize"
     QEMU_MACHINE "mps2-an386"
     QEMU_CPU "cortex-m4"

test-support/picolibc-test-wrapper.py

@@ -17,10 +17,10 @@
     # computations on types implemented in software
     # https://github.com/picolibc/picolibc/pull/500
     "picolibc_armv7m_soft_fpv4_sp_d16-build/test/math_errhandling",
-    "picolibc_armv7em_hard_fpv4_sp_d16-build/test/math_errhandling",
+    "picolibc_armv7m_hard_fpv4_sp_d16-build/test/math_errhandling",
     "picolibc_armv8.1m.main_hard_fp_nomve-build/test/math_errhandling",
     "picolibc_armv7m_soft_fpv4_sp_d16_exn_rtti-build/test/math_errhandling",
-    "picolibc_armv7em_hard_fpv4_sp_d16_exn_rtti-build/test/math_errhandling",
+    "picolibc_armv7m_hard_fpv4_sp_d16_exn_rtti-build/test/math_errhandling",
     "picolibc_armv8.1m.main_hard_fp_nomve_exn_rtti-build/test/math_errhandling",
     "picolibc_armv8.1m.main_hard_nofp_mve-build/test/fenv",
     "picolibc_armv8.1m.main_hard_nofp_mve-build/test/math_errhandling",

test/multilib/armv7m.test

@@ -1,9 +1,28 @@
-# RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=none | FileCheck %s
-# RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=none -mfloat-abi=softfp | FileCheck %s
-# CHECK: arm-none-eabi/armv7m_soft_nofp_exn_rtti{{$}}
-# CHECK-EMPTY:
+# RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=none | FileCheck %s --check-prefix=NONE
+# RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=none -mfloat-abi=softfp | FileCheck %s --check-prefix=NONE
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabi -mfpu=none -mfloat-abi=softfp | FileCheck %s --check-prefix=NONE
+# NONE: arm-none-eabi/armv7m_soft_nofp_exn_rtti{{$}}
+# NONE-EMPTY:
 
 # RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=fpv4-sp-d16 -mfloat-abi=softfp | FileCheck --check-prefix=SOFT-FPV4 %s
 # RUN: %clang -print-multi-directory --target=armv7m-none-eabi -mfpu=fpv5-d16 -mfloat-abi=softfp | FileCheck --check-prefix=SOFT-FPV4 %s
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabi -mfpu=fpv4-sp-d16 -mfloat-abi=softfp | FileCheck --check-prefix=SOFT-FPV4 %s
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabi -mfpu=fpv5-d16 -mfloat-abi=softfp | FileCheck --check-prefix=SOFT-FPV4 %s
 # SOFT-FPV4: arm-none-eabi/armv7m_soft_fpv4_sp_d16_exn_rtti{{$}}
 # SOFT-FPV4-EMPTY:
+#
+# RUN: %clang -print-multi-directory --target=armv7m-none-eabihf -mfpu=fpv4-sp-d16 | FileCheck --check-prefix=FPV4 %s
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabihf -mfpu=fpv4-sp-d16 | FileCheck --check-prefix=FPV4 %s
+# FPV4: arm-none-eabi/armv7m_hard_fpv4_sp_d16_exn_rtti{{$}}
+# FPV4-EMPTY:
+#
+# RUN: %clang -print-multi-directory --target=armv7m-none-eabihf -mfpu=fpv5-d16 | FileCheck --check-prefix=FPV5 %s
+# RUN: %clang -print-multi-directory --target=armv7em-none-eabihf -mfpu=fpv5-d16 | FileCheck --check-prefix=FPV5 %s
+# FPV5: arm-none-eabi/armv7m_hard_fpv5_d16_exn_rtti{{$}}
+# FPV5-EMPTY:
+
+# %clang -print-multi-directory --target=arm-none-eabi   -mcpu=cortex-m3 | FileCheck %s --check-prefix=NONE
+# %clang -print-multi-directory --target=arm-none-eabi   -mcpu=cortex-m4 | FileCheck %s --check-prefix=SOFT-FPV4
+# %clang -print-multi-directory --target=arm-none-eabihf -mcpu=cortex-m4 | FileCheck %s --check-prefix=FPV4
+# %clang -print-multi-directory --target=arm-none-eabi   -mcpu=cortex-m7 | FileCheck %s --check-prefix=SOFT-FPV4
+# %clang -print-multi-directory --target=arm-none-eabihf -mcpu=cortex-m7 | FileCheck %s --check-prefix=FPV4