[RISCV] Add CFI directives for RISCV prologue/epilog.

In order to generate correct debug frame information, it needs to
generate CFI information in prologue and epilog.

Differential Revision: https://reviews.llvm.org/D61773

llvm-svn: 363120
diff --git a/llvm/test/CodeGen/RISCV/frame-info.ll b/llvm/test/CodeGen/RISCV/frame-info.ll
new file mode 100644
index 0000000..9022fc3
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/frame-info.ll
@@ -0,0 +1,66 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 < %s | FileCheck -check-prefix=RV32 %s
+; RUN: llc -mtriple=riscv64 < %s | FileCheck -check-prefix=RV64 %s
+
+define void @foo(i32 signext %size) {
+; RV32-LABEL: foo:
+; RV32:       # %bb.0: # %entry
+; RV32-NEXT:    addi sp, sp, -16
+; RV32-NEXT:    .cfi_def_cfa_offset 16
+; RV32-NEXT:    sw ra, 12(sp)
+; RV32-NEXT:    sw s0, 8(sp)
+; RV32-NEXT:    .cfi_offset ra, -4
+; RV32-NEXT:    .cfi_offset s0, -8
+; RV32-NEXT:    addi s0, sp, 16
+; RV32-NEXT:    .cfi_def_cfa s0, 0
+; RV32-NEXT:    addi a0, a0, 15
+; RV32-NEXT:    andi a0, a0, -16
+; RV32-NEXT:    sub a0, sp, a0
+; RV32-NEXT:    mv sp, a0
+; RV32-NEXT:    call bar
+; RV32-NEXT:    addi sp, s0, -16
+; RV32-NEXT:    lw s0, 8(sp)
+; RV32-NEXT:    .cfi_def_cfa sp, 16
+; RV32-NEXT:    lw ra, 12(sp)
+; RV32-NEXT:    .cfi_restore ra
+; RV32-NEXT:    .cfi_restore s0
+; RV32-NEXT:    addi sp, sp, 16
+; RV32-NEXT:    .cfi_def_cfa_offset 0
+; RV32-NEXT:    ret
+;
+; RV64-LABEL: foo:
+; RV64:       # %bb.0: # %entry
+; RV64-NEXT:    addi sp, sp, -16
+; RV64-NEXT:    .cfi_def_cfa_offset 16
+; RV64-NEXT:    sd ra, 8(sp)
+; RV64-NEXT:    sd s0, 0(sp)
+; RV64-NEXT:    .cfi_offset ra, -8
+; RV64-NEXT:    .cfi_offset s0, -16
+; RV64-NEXT:    addi s0, sp, 16
+; RV64-NEXT:    .cfi_def_cfa s0, 0
+; RV64-NEXT:    addi a1, zero, 1
+; RV64-NEXT:    slli a1, a1, 33
+; RV64-NEXT:    addi a1, a1, -16
+; RV64-NEXT:    slli a0, a0, 32
+; RV64-NEXT:    srli a0, a0, 32
+; RV64-NEXT:    addi a0, a0, 15
+; RV64-NEXT:    and a0, a0, a1
+; RV64-NEXT:    sub a0, sp, a0
+; RV64-NEXT:    mv sp, a0
+; RV64-NEXT:    call bar
+; RV64-NEXT:    addi sp, s0, -16
+; RV64-NEXT:    ld s0, 0(sp)
+; RV64-NEXT:    .cfi_def_cfa sp, 16
+; RV64-NEXT:    ld ra, 8(sp)
+; RV64-NEXT:    .cfi_restore ra
+; RV64-NEXT:    .cfi_restore s0
+; RV64-NEXT:    addi sp, sp, 16
+; RV64-NEXT:    .cfi_def_cfa_offset 0
+; RV64-NEXT:    ret
+entry:
+  %0 = alloca i8, i32 %size, align 16
+  call void @bar(i8* nonnull %0) #2
+  ret void
+}
+
+declare void @bar(i8*)