[RISCV] Support .option rvc and norvc assembler directives

These directives allow the 'C' (compressed) extension to be enabled/disabled 
within a single file.

Differential Revision: https://reviews.llvm.org/D45864
Patch by Kito Cheng

llvm-svn: 332107

4 files changed, 137 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/RISCV/option-norvc.ll b/llvm/test/CodeGen/RISCV/option-norvc.ll
new file mode 100644
index 00000000000..381fb37735d
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/option-norvc.ll
@@ -0,0 +1,15 @@
+; RUN: llc -mtriple=riscv32 -mattr=+c  -filetype=obj < %s\
+; RUN: | llvm-objdump -triple=riscv32 -mattr=+c -d -riscv-no-aliases -\
+; RUN: | FileCheck -check-prefix=CHECK %s
+
+; This test demonstrates that .option norvc has no effect on codegen when
+; emitting an ELF directly.
+
+define i32 @add(i32 %a, i32 %b) nounwind {
+; CHECK-LABEL: add:
+; CHECK:    c.add a0, a1
+; CHECK-NEXT:    c.jr ra
+  tail call void asm sideeffect ".option norvc", ""()
+  %add = add nsw i32 %b, %a
+  ret i32 %add
+}
diff --git a/llvm/test/CodeGen/RISCV/option-rvc.ll b/llvm/test/CodeGen/RISCV/option-rvc.ll
new file mode 100644
index 00000000000..3c207bd424f
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/option-rvc.ll
@@ -0,0 +1,15 @@
+; RUN: llc -mtriple=riscv32 -filetype=obj < %s\
+; RUN: | llvm-objdump -triple=riscv32 -mattr=+c -d -riscv-no-aliases -\
+; RUN: | FileCheck -check-prefix=CHECK %s
+
+; This test demonstrates that .option norvc has no effect on codegen when
+; emitting an ELF directly.
+
+define i32 @add(i32 %a, i32 %b) nounwind {
+; CHECK-LABEL: add:
+; CHECK:    add a0, a1, a0
+; CHECK-NEXT:    jalr zero, ra, 0
+  tail call void asm sideeffect ".option rvc", ""()
+  %add = add nsw i32 %b, %a
+  ret i32 %add
+}
diff --git a/llvm/test/MC/RISCV/option-invalid.s b/llvm/test/MC/RISCV/option-invalid.s
new file mode 100644
index 00000000000..ec9e8e030d7
--- /dev/null
+++ b/llvm/test/MC/RISCV/option-invalid.s
@@ -0,0 +1,17 @@
+# RUN: not llvm-mc -triple riscv32 < %s 2>&1 \
+# RUN: | FileCheck -check-prefixes=CHECK %s
+
+# CHECK: error: unexpected token, expected identifier
+.option
+
+# CHECK: error: unexpected token, expected identifier
+.option 123
+
+# CHECK: error: unexpected token, expected identifier
+.option "str"
+
+# CHECK: error: unexpected token, expected end of statement
+.option rvc foo
+
+# CHECK: warning: unknown option, expected 'rvc' or 'norvc'
+.option bar
diff --git a/llvm/test/MC/RISCV/option-rvc.s b/llvm/test/MC/RISCV/option-rvc.s
new file mode 100644
index 00000000000..129eae5bf79
--- /dev/null
+++ b/llvm/test/MC/RISCV/option-rvc.s
@@ -0,0 +1,90 @@
+# RUN: llvm-mc -triple riscv32 -show-encoding < %s \
+# RUN: | FileCheck -check-prefixes=CHECK,CHECK-ALIAS %s
+# RUN: llvm-mc -triple riscv32 -show-encoding \
+# RUN: -riscv-no-aliases <%s | FileCheck -check-prefixes=CHECK,CHECK-INST %s
+# RUN: llvm-mc -triple riscv32 -filetype=obj < %s \
+# RUN: | llvm-objdump  -triple riscv32 -mattr=+c -d - \
+# RUN: | FileCheck -check-prefixes=CHECK-BYTES,CHECK-ALIAS %s
+# RUN: llvm-mc -triple riscv32 -filetype=obj < %s \
+# RUN: | llvm-objdump  -triple riscv32 -mattr=+c -d -riscv-no-aliases - \
+# RUN: | FileCheck -check-prefixes=CHECK-BYTES,CHECK-INST %s
+
+# RUN: llvm-mc -triple riscv64 -show-encoding < %s \
+# RUN: | FileCheck -check-prefixes=CHECK-ALIAS %s
+# RUN: llvm-mc -triple riscv64 -show-encoding \
+# RUN: -riscv-no-aliases <%s | FileCheck -check-prefixes=CHECK-INST %s
+# RUN: llvm-mc -triple riscv64 -filetype=obj < %s \
+# RUN: | llvm-objdump  -triple riscv64 -mattr=+c -d - \
+# RUN: | FileCheck -check-prefixes=CHECK-BYTES,CHECK-ALIAS %s
+# RUN: llvm-mc -triple riscv64 -filetype=obj < %s \
+# RUN: | llvm-objdump  -triple riscv64 -mattr=+c -d -riscv-no-aliases - \
+# RUN: | FileCheck -check-prefixes=CHECK-BYTES,CHECK-INST %s
+
+# CHECK-BYTES: 13 85 05 00
+# CHECK-ALIAS: mv a0, a1
+# CHECK-INST: addi a0, a1, 0
+# CHECK: # encoding:  [0x13,0x85,0x05,0x00]
+addi a0, a1, 0
+
+# CHECK-BYTES: 13 04 c1 3f
+# CHECK-ALIAS: addi s0, sp, 1020
+# CHECK-INST: addi s0, sp, 1020
+# CHECK: # encoding:  [0x13,0x04,0xc1,0x3f]
+addi s0, sp, 1020
+
+
+# CHECK: .option rvc
+.option rvc
+# CHECK-BYTES: 2e 85
+# CHECK-ALIAS: add a0, zero, a1
+# CHECK-INST: c.mv a0, a1
+# CHECK: # encoding:  [0x2e,0x85]
+addi a0, a1, 0
+
+# CHECK-BYTES: e0 1f
+# CHECK-ALIAS: addi s0, sp, 1020
+# CHECK-INST: c.addi4spn s0, sp, 1020
+# CHECK: # encoding:  [0xe0,0x1f]
+addi s0, sp, 1020
+
+# CHECK: .option norvc
+.option norvc
+# CHECK-BYTES: 13 85 05 00
+# CHECK-ALIAS: mv a0, a1
+# CHECK-INST: addi a0, a1, 0
+# CHECK: # encoding:  [0x13,0x85,0x05,0x00]
+addi a0, a1, 0
+
+# CHECK-BYTES: 13 04 c1 3f
+# CHECK-ALIAS: addi s0, sp, 1020
+# CHECK-INST: addi s0, sp, 1020
+# CHECK: # encoding:  [0x13,0x04,0xc1,0x3f]
+addi s0, sp, 1020
+
+# CHECK: .option rvc
+.option rvc
+# CHECK-BYTES: 2e 85
+# CHECK-ALIAS: add a0, zero, a1
+# CHECK-INST: c.mv a0, a1
+# CHECK: # encoding:  [0x2e,0x85]
+addi a0, a1, 0
+
+# CHECK-BYTES: e0 1f
+# CHECK-ALIAS: addi s0, sp, 1020
+# CHECK-INST: c.addi4spn s0, sp, 1020
+# CHECK: # encoding:  [0xe0,0x1f]
+addi s0, sp, 1020
+
+# CHECK: .option norvc
+.option norvc
+# CHECK-BYTES: 13 85 05 00
+# CHECK-ALIAS: mv a0, a1
+# CHECK-INST: addi a0, a1, 0
+# CHECK: # encoding:  [0x13,0x85,0x05,0x00]
+addi a0, a1, 0
+
+# CHECK-BYTES: 13 04 c1 3f
+# CHECK-ALIAS: addi s0, sp, 1020
+# CHECK-INST: addi s0, sp, 1020
+# CHECK: # encoding:  [0x13,0x04,0xc1,0x3f]
+addi s0, sp, 1020