From a23f18a6a6b647c7872e605662d8803b15a01e4d Mon Sep 17 00:00:00 2001
From: Andrew Waterman <waterman@s141.Millennium.Berkeley.EDU>
Date: Sat, 11 Jun 2011 16:12:48 -0700
Subject: [PATCH] [xcc] instructions now set PC explicitly

---
 riscv/decode.h       | 14 ++++++++++++++
 riscv/insns/beq.h    |  2 +-
 riscv/insns/bge.h    |  2 +-
 riscv/insns/bgeu.h   |  2 +-
 riscv/insns/blt.h    |  2 +-
 riscv/insns/bltu.h   |  2 +-
 riscv/insns/bne.h    |  2 +-
 riscv/insns/c_addi.h |  6 +++---
 riscv/insns/c_beq.h  |  2 +-
 riscv/insns/c_bne.h  |  2 +-
 riscv/insns/c_j.h    |  2 +-
 riscv/insns/eret.h   |  2 +-
 riscv/insns/j.h      |  2 +-
 riscv/insns/jal.h    |  2 +-
 riscv/insns/jalr_c.h |  6 +++---
 15 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/riscv/decode.h b/riscv/decode.h
index 59ca87a1..6dfe6b97 100644
--- a/riscv/decode.h
+++ b/riscv/decode.h
@@ -212,6 +212,20 @@ private:
 #define sext_xprlen(x) ((sreg_t(x) << (64-xprlen)) >> (64-xprlen))
 #define zext_xprlen(x) ((reg_t(x) << (64-xprlen)) >> (64-xprlen))
 
+#ifndef RISCV_ENABLE_RVC
+# define set_pc(x) \
+  do { if((x) & (sizeof(insn_t)-1)) \
+       { badvaddr = (x); throw trap_instruction_address_misaligned; } \
+       npc = (x); \
+     } while(0)
+#else
+# define set_pc(x) \
+  do { if((x) & ((sr & SR_EC) ? 1 : 3)) \
+       { badvaddr = (x); throw trap_instruction_address_misaligned; } \
+       npc = (x); \
+     } while(0)
+#endif
+
 // RVC stuff
 
 #define INSN_IS_RVC(x) (((x) & 0x3) < 0x3)
diff --git a/riscv/insns/beq.h b/riscv/insns/beq.h
index 072b7b84..7b26488e 100644
--- a/riscv/insns/beq.h
+++ b/riscv/insns/beq.h
@@ -1,2 +1,2 @@
 if(cmp_trunc(RS1) == cmp_trunc(RS2))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/bge.h b/riscv/insns/bge.h
index 45dcc2ee..dca544b4 100644
--- a/riscv/insns/bge.h
+++ b/riscv/insns/bge.h
@@ -1,2 +1,2 @@
 if(sreg_t(cmp_trunc(RS1)) >= sreg_t(cmp_trunc(RS2)))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/bgeu.h b/riscv/insns/bgeu.h
index 2ba3fa81..63254669 100644
--- a/riscv/insns/bgeu.h
+++ b/riscv/insns/bgeu.h
@@ -1,2 +1,2 @@
 if(cmp_trunc(RS1) >= cmp_trunc(RS2))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/blt.h b/riscv/insns/blt.h
index 3ffd20e7..d84fd7a3 100644
--- a/riscv/insns/blt.h
+++ b/riscv/insns/blt.h
@@ -1,2 +1,2 @@
 if(sreg_t(cmp_trunc(RS1)) < sreg_t(cmp_trunc(RS2)))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/bltu.h b/riscv/insns/bltu.h
index 186dcbef..250fd4f9 100644
--- a/riscv/insns/bltu.h
+++ b/riscv/insns/bltu.h
@@ -1,2 +1,2 @@
 if(cmp_trunc(RS1) < cmp_trunc(RS2))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/bne.h b/riscv/insns/bne.h
index 39b0b19e..f7757214 100644
--- a/riscv/insns/bne.h
+++ b/riscv/insns/bne.h
@@ -1,2 +1,2 @@
 if(cmp_trunc(RS1) != cmp_trunc(RS2))
-  npc = BRANCH_TARGET;
+  set_pc(BRANCH_TARGET);
diff --git a/riscv/insns/c_addi.h b/riscv/insns/c_addi.h
index c716f699..448e31a3 100644
--- a/riscv/insns/c_addi.h
+++ b/riscv/insns/c_addi.h
@@ -1,10 +1,10 @@
 require_rvc;
 if(CRD_REGNUM == 0)
 {
-  reg_t temp = npc;
-  npc = CRS1;
+  reg_t temp = CRS1;
   if(CIMM6 & 0x20)
-    RA = temp;
+    RA = npc;
+  set_pc(temp);
 }
 else
   CRD = sext_xprlen(CRS2 + CIMM6);
diff --git a/riscv/insns/c_beq.h b/riscv/insns/c_beq.h
index 4ceaba26..031d96db 100644
--- a/riscv/insns/c_beq.h
+++ b/riscv/insns/c_beq.h
@@ -1,3 +1,3 @@
 require_rvc;
 if(cmp_trunc(CRS1S) == cmp_trunc(CRS2S))
-  npc = CBRANCH_TARGET;
+  set_pc(CBRANCH_TARGET);
diff --git a/riscv/insns/c_bne.h b/riscv/insns/c_bne.h
index 59f257b5..caf92290 100644
--- a/riscv/insns/c_bne.h
+++ b/riscv/insns/c_bne.h
@@ -1,3 +1,3 @@
 require_rvc;
 if(cmp_trunc(CRS1S) != cmp_trunc(CRS2S))
-  npc = CBRANCH_TARGET;
+  set_pc(CBRANCH_TARGET);
diff --git a/riscv/insns/c_j.h b/riscv/insns/c_j.h
index 87ee0150..5ba9c735 100644
--- a/riscv/insns/c_j.h
+++ b/riscv/insns/c_j.h
@@ -1,2 +1,2 @@
 require_rvc;
-npc = CJUMP_TARGET;
+set_pc(CJUMP_TARGET);
diff --git a/riscv/insns/eret.h b/riscv/insns/eret.h
index 37e85885..46d5bed2 100644
--- a/riscv/insns/eret.h
+++ b/riscv/insns/eret.h
@@ -2,4 +2,4 @@ require_supervisor;
 if(sr & SR_ET)
   throw trap_illegal_instruction;
 set_sr(((sr & SR_PS) ? sr : (sr & ~SR_S)) | SR_ET);
-npc = epc;
+set_pc(epc);
diff --git a/riscv/insns/j.h b/riscv/insns/j.h
index 8abe0ba2..3a4da2a7 100644
--- a/riscv/insns/j.h
+++ b/riscv/insns/j.h
@@ -1 +1 @@
-npc = JUMP_TARGET;
+set_pc(JUMP_TARGET);
diff --git a/riscv/insns/jal.h b/riscv/insns/jal.h
index bca7241e..41dc4037 100644
--- a/riscv/insns/jal.h
+++ b/riscv/insns/jal.h
@@ -1,2 +1,2 @@
 RA = npc;
-npc = JUMP_TARGET;
+set_pc(JUMP_TARGET);
diff --git a/riscv/insns/jalr_c.h b/riscv/insns/jalr_c.h
index 536ebbf7..91be911b 100644
--- a/riscv/insns/jalr_c.h
+++ b/riscv/insns/jalr_c.h
@@ -1,3 +1,3 @@
-reg_t temp = npc;
-npc = RS1 + SIMM;
-RD = temp;
+reg_t temp = RS1;
+RD = npc;
+set_pc(temp + SIMM);