Add ISA-dependent settings for RISC-V.

meta/isa/riscv/__init__.py

@@ -27,7 +27,7 @@ RV32G / RV64G
 
 import defs
 import encodings
+import settings
 
 # Re-export the primary target ISA definition.
 isa = defs.isa
-

meta/isa/riscv/encodings.py

@@ -2,7 +2,6 @@
 RISC-V Encodings.
 """
 from cretonne import base
-from cretonne.types import i32, i64
 from defs import RV32, RV64
 from recipes import OP, R
 

meta/isa/riscv/recipes.py

@@ -18,27 +18,33 @@ from cretonne.formats import Binary
 # Encbits for the 32-bit recipes are opcode[6:2] | (funct3 << 5) | ...
 # The functions below encode the encbits.
 
+
 def LOAD(funct3):
     assert funct3 <= 0b111
     return 0b00000 | (funct3 << 5)
 
+
 def STORE(funct3):
     assert funct3 <= 0b111
     return 0b01000 | (funct3 << 5)
 
+
 def BRANCH(funct3):
     assert funct3 <= 0b111
     return 0b11000 | (funct3 << 5)
 
+
 def OPIMM(funct3):
     assert funct3 <= 0b111
     return 0b00100 | (funct3 << 5)
 
+
 def OP(funct3, funct7):
     assert funct3 <= 0b111
     assert funct7 <= 0b1111111
     return 0b01100 | (funct3 << 5) | (funct7 << 8)
 
+
 # R-type 32-bit instructions: These are mostly binary arithmetic instructions.
 # The encbits are `opcode[6:2] | (funct3 << 5) | (funct7 << 8)
 R = EncRecipe('R', Binary)

meta/isa/riscv/settings.py

@@ -0,0 +1,15 @@
+"""
+RISC-V settings.
+"""
+
+from cretonne import SettingGroup, BoolSetting
+from defs import isa
+
+isa.settings = SettingGroup('riscv')
+
+supports_m = BoolSetting("CPU supports the 'M' extension (mul/div)")
+supports_a = BoolSetting("CPU supports the 'A' extension (atomics)")
+supports_f = BoolSetting("CPU supports the 'F' extension (float)")
+supports_d = BoolSetting("CPU supports the 'D' extension (double)")
+
+isa.settings.close(globals())