[clang] [llvm] [ARM] Save floating point registers and status registers with save_fp function attribute (PR #89654)

[Benson Chu via cfe-commits]

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@@ -0,0 +1,34 @@
+// REQUIRES: arm-registered-target
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-r5 -mfpu=vfpv3-d16 -marm -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-R
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-r5 -mfpu=vfpv3-d16 -mthumb -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-R
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-r4 -mfpu=vfpv3-d16 -marm -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-R
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-r4 -mfpu=vfpv3-d16 -mthumb -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-R
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-M
+// RUN: %clang -target arm-none-none-eabihf -mcpu=cortex-m33 -mfpu=fpv5-sp-d16 -S -o - %s \
+// RUN: | FileCheck %s --check-prefix=CHECK-M
+
+void bar();
+
+__attribute__((interrupt_save_fp)) void test_generic_interrupt() {
+    // CHECK-R:      vmrs	r4, fpscr
+    // CHECK-R-NEXT: vmrs	r5, fpexc
+    // CHECK-R-NEXT: .save  {fpscr, fpexc}
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pestctrl wrote:

I have reverted that syntax change. We had initially rolled it out internally, and later found that our assembler didn't like that syntax change, so we rolled it back. I forgot to roll it back on the upstream branch. 

To our understanding, the .save directive is for unwinding, and only accepts GPR's. .vsave isn't the correct directive to use either, since those only accept DPR's. In the end, we decided to just have those .save's refer to the actual GPR's. 

https://github.com/llvm/llvm-project/pull/89654