[Tinycc-devel] [PATCH 9/9] arm-asm: Raise error if asm_data_processing_opcode and asm_shift_opcode try to use PC for register-controlled shifts

[Danny Milosavljevic]

---
 arm-asm.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/arm-asm.c b/arm-asm.c
index b565127..6eb680a 100644
--- a/arm-asm.c
+++ b/arm-asm.c
@@ -529,6 +529,13 @@ static void asm_data_processing_opcode(TCCState *s1, int 
token)
         return;
     } else {
         uint32_t opcode = 0;
+        if (nb_shift && shift.type == OP_REG32) {
+            if ((ops[0].type == OP_REG32 && ops[0].reg == 15) ||
+                (ops[1].type == OP_REG32 && ops[1].reg == 15)) {
+                tcc_error("Using the 'pc' register in data processing 
instructions that have a register-controlled shift is not implemented by ARM");
+                return;
+            }
+        }
 
         // data processing (general case):
         // operands:
@@ -655,9 +662,10 @@ static void asm_shift_opcode(TCCState *s1, int token)
         return;
     }
 
-    if (ops[0].type != OP_REG32)
+    if (ops[0].type != OP_REG32) {
         expect("(destination operand) register");
-    else
+        return;
+    } else
         operands |= ENCODE_RD(ops[0].reg);
 
     if (nb_ops == 2) {
@@ -694,6 +702,13 @@ static void asm_shift_opcode(TCCState *s1, int token)
         break;
     }
 
+    if (ops[2].type == OP_REG32) {
+        if ((ops[0].type == OP_REG32 && ops[0].reg == 15) ||
+            (ops[1].type == OP_REG32 && ops[1].reg == 15)) {
+            tcc_error("Using the 'pc' register in data processing instructions 
that have a register-controlled shift is not implemented by ARM");
+        }
+    }
+
     if (operands & ENCODE_IMMEDIATE_FLAG)
         operands |= asm_encode_rotation(&ops[2]);
     else