Implement riscv64 LLVM backend

This enables a registerised build for the riscv64 architecture.

4 files changed, 141 insertions, 1 deletions

diff --git a/includes/CodeGen.Platform.hs b/includes/CodeGen.Platform.hs
index b00acfa38a..8c942662e6 100644
--- a/includes/CodeGen.Platform.hs
+++ b/includes/CodeGen.Platform.hs
@@ -380,6 +380,74 @@ import GHC.Platform.Reg
 # define f14 30
 # define f15 31
 
+#elif defined(MACHREGS_riscv64)
+
+# define zero 0
+# define ra   1
+# define sp   2
+# define gp   3
+# define tp   4
+# define t0   5
+# define t1   6
+# define t2   7
+# define s0   8
+# define s1   9
+# define a0  10
+# define a1  11
+# define a2  12
+# define a3  13
+# define a4  14
+# define a5  15
+# define a6  16
+# define a7  17
+# define s2  18
+# define s3  19
+# define s4  20
+# define s5  21
+# define s6  22
+# define s7  23
+# define s8  24
+# define s9  25
+# define s10 26
+# define s11 27
+# define t3  28
+# define t4  29
+# define t5  30
+# define t6  31
+
+# define ft0  32
+# define ft1  33
+# define ft2  34
+# define ft3  35
+# define ft4  36
+# define ft5  37
+# define ft6  38
+# define ft7  39
+# define fs0  40
+# define fs1  41
+# define fa0  42
+# define fa1  43
+# define fa2  44
+# define fa3  45
+# define fa4  46
+# define fa5  47
+# define fa6  48
+# define fa7  49
+# define fs2  50
+# define fs3  51
+# define fs4  52
+# define fs5  53
+# define fs6  54
+# define fs7  55
+# define fs8  56
+# define fs9  57
+# define fs10 58
+# define fs11 59
+# define ft8  60
+# define ft9  61
+# define ft10 62
+# define ft11 63
+
 #endif
 
 callerSaves :: GlobalReg -> Bool
@@ -667,7 +735,7 @@ globalRegMaybe :: GlobalReg -> Maybe RealReg
 #if defined(MACHREGS_i386) || defined(MACHREGS_x86_64) \
     || defined(MACHREGS_sparc) || defined(MACHREGS_powerpc) \
     || defined(MACHREGS_arm) || defined(MACHREGS_aarch64) \
-    || defined(MACHREGS_s390x)
+    || defined(MACHREGS_s390x) || defined(MACHREGS_riscv64)
 # if defined(REG_Base)
 globalRegMaybe BaseReg                  = Just (RealRegSingle REG_Base)
 # endif
diff --git a/includes/stg/MachRegs.h b/includes/stg/MachRegs.h
index a04452e0e7..4b0991891e 100644
--- a/includes/stg/MachRegs.h
+++ b/includes/stg/MachRegs.h
@@ -663,6 +663,68 @@ the stack. See Note [Overlapping global registers] for implications.
 #define CALLER_SAVES_D5
 #define CALLER_SAVES_D6
 
+/* -----------------------------------------------------------------------------
+   The riscv64 register mapping
+
+   Register    | Role(s)                                 | Call effect
+   ------------+-----------------------------------------+-------------
+   zero        | Hard-wired zero                         | -
+   ra          | Return address                          | caller-saved
+   sp          | Stack pointer                           | callee-saved
+   gp          | Global pointer                          | callee-saved
+   tp          | Thread pointer                          | callee-saved
+   t0,t1,t2    | -                                       | caller-saved
+   s0          | Frame pointer                           | callee-saved
+   s1          | -                                       | callee-saved
+   a0,a1       | Arguments / return values               | caller-saved
+   a2..a7      | Arguments                               | caller-saved
+   s2..s11     | -                                       | callee-saved
+   t3..t6      | -                                       | caller-saved
+   ft0..ft7    | -                                       | caller-saved
+   fs0,fs1     | -                                       | callee-saved
+   fa0,fa1     | Arguments / return values               | caller-saved
+   fa2..fa7    | Arguments                               | caller-saved
+   fs2..fs11   | -                                       | callee-saved
+   ft8..ft11   | -                                       | caller-saved
+
+   Each general purpose register as well as each floating-point
+   register is 64 bits wide.
+
+   -------------------------------------------------------------------------- */
+
+#elif defined(MACHREGS_riscv64)
+
+#define REG(x) __asm__(#x)
+
+#define REG_Base        s1
+#define REG_Sp          s2
+#define REG_Hp          s3
+#define REG_R1          s4
+#define REG_R2          s5
+#define REG_R3          s6
+#define REG_R4          s7
+#define REG_R5          s8
+#define REG_R6          s9
+#define REG_R7          s10
+#define REG_SpLim       s11
+
+#define REG_F1          fs0
+#define REG_F2          fs1
+#define REG_F3          fs2
+#define REG_F4          fs3
+#define REG_F5          fs4
+#define REG_F6          fs5
+
+#define REG_D1          fs6
+#define REG_D2          fs7
+#define REG_D3          fs8
+#define REG_D4          fs9
+#define REG_D5          fs10
+#define REG_D6          fs11
+
+#define MAX_REAL_FLOAT_REG   6
+#define MAX_REAL_DOUBLE_REG  6
+
 #else
 
 #error Cannot find platform to give register info for
diff --git a/includes/stg/MachRegsForHost.h b/includes/stg/MachRegsForHost.h
index 3597b2be90..e902d528f6 100644
--- a/includes/stg/MachRegsForHost.h
+++ b/includes/stg/MachRegsForHost.h
@@ -71,6 +71,10 @@
 #define MACHREGS_s390x    1
 #endif
 
+#if defined(riscv64_HOST_ARCH)
+#define MACHREGS_riscv64  1
+#endif
+
 #endif
 
 #include "MachRegs.h"
diff --git a/includes/stg/SMP.h b/includes/stg/SMP.h
index 589bde8266..57eb618592 100644
--- a/includes/stg/SMP.h
+++ b/includes/stg/SMP.h
@@ -395,6 +395,8 @@ write_barrier(void) {
     __asm__ __volatile__ ("" : : : "memory");
 #elif defined(arm_HOST_ARCH) || defined(aarch64_HOST_ARCH)
     __asm__ __volatile__ ("dmb  st" : : : "memory");
+#elif defined(riscv64_HOST_ARCH)
+    __asm__ __volatile__ ("fence w,w" : : : "memory");
 #else
 #error memory barriers unimplemented on this architecture
 #endif
@@ -419,6 +421,8 @@ store_load_barrier(void) {
     __asm__ __volatile__ ("dmb" : : : "memory");
 #elif defined(aarch64_HOST_ARCH)
     __asm__ __volatile__ ("dmb sy" : : : "memory");
+#elif defined(riscv64_HOST_ARCH)
+    __asm__ __volatile__ ("fence w,r" : : : "memory");
 #else
 #error memory barriers unimplemented on this architecture
 #endif
@@ -444,6 +448,8 @@ load_load_barrier(void) {
     __asm__ __volatile__ ("dmb" : : : "memory");
 #elif defined(aarch64_HOST_ARCH)
     __asm__ __volatile__ ("dmb sy" : : : "memory");
+#elif defined(riscv64_HOST_ARCH)
+    __asm__ __volatile__ ("fence w,r" : : : "memory");
 #else
 #error memory barriers unimplemented on this architecture
 #endif