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[Tinycc-devel] [PATCH] arm-asm: Support bigger immediates for data proce
From: |
Danny Milosavljevic |
Subject: |
[Tinycc-devel] [PATCH] arm-asm: Support bigger immediates for data processing instructions |
Date: |
Sun, 3 Jan 2021 02:33:23 +0100 |
---
arm-asm.c | 57 ++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 17 deletions(-)
diff --git a/arm-asm.c b/arm-asm.c
index 53fdc23..99f2f3a 100644
--- a/arm-asm.c
+++ b/arm-asm.c
@@ -550,6 +550,8 @@ static void asm_data_processing_opcode(TCCState *s1, int
token)
return;
} else {
uint32_t opcode = 0;
+ uint32_t immediate_value;
+ uint8_t half_immediate_rotation;
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)) {
@@ -583,11 +585,25 @@ static void asm_data_processing_opcode(TCCState *s1, int
token)
operands |= ops[2].reg;
break;
case OP_IM8:
+ case OP_IM32:
operands |= ENCODE_IMMEDIATE_FLAG;
- operands |= ops[2].e.v;
- break;
+ immediate_value = ops[2].e.v;
+ for (half_immediate_rotation = 0; half_immediate_rotation < 16;
++half_immediate_rotation) {
+ if (immediate_value >= 0x00 && immediate_value < 0x100)
+ break;
+ // rotate left by two
+ immediate_value = ((immediate_value & 0x3FFFFFFF) << 2) |
((immediate_value & 0xC0000000) >> 30);
+ }
+ if (half_immediate_rotation >= 16) {
+ /* fallthrough */
+ } else {
+ operands |= immediate_value;
+ operands |= half_immediate_rotation << 8;
+ break;
+ }
case OP_IM8N: // immediate negative value
operands |= ENCODE_IMMEDIATE_FLAG;
+ immediate_value = ops[2].e.v;
/* Instruction swapping:
0001 = EOR - Rd:= Op1 EOR Op2 -> difficult
0011 = RSB - Rd:= Op2 - Op1 -> difficult
@@ -597,54 +613,61 @@ static void asm_data_processing_opcode(TCCState *s1, int
token)
1100 = ORR - Rd:= Op1 OR Op2 -> difficult
*/
switch (opcode_nos) {
-#if 0
case 0x0: // AND - Rd:= Op1 AND Op2
opcode = 0xe << 21; // BIC
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
case 0x2: // SUB - Rd:= Op1 - Op2
opcode = 0x4 << 21; // ADD
- operands |= (-ops[2].e.v) & 0xFF;
+ immediate_value = -immediate_value;
break;
case 0x4: // ADD - Rd:= Op1 + Op2
opcode = 0x2 << 21; // SUB
- operands |= (-ops[2].e.v) & 0xFF;
+ immediate_value = -immediate_value;
break;
case 0x5: // ADC - Rd:= Op1 + Op2 + C
opcode = 0x6 << 21; // SBC
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
case 0x6: // SBC - Rd:= Op1 - Op2 + C
opcode = 0x5 << 21; // ADC
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
-#endif
case 0xa: // CMP - CC on: Op1 - Op2
opcode = 0xb << 21; // CMN
- operands |= (-ops[2].e.v) & 0xFF;
+ immediate_value = -immediate_value;
break;
case 0xb: // CMN - CC on: Op1 + Op2
opcode = 0xa << 21; // CMP
- operands |= (-ops[2].e.v) & 0xFF;
+ immediate_value = -immediate_value;
break;
- // moveq r1, r3: 0x01a01003; mov Rd, Op2
case 0xd: // MOV - Rd:= Op2
opcode = 0xf << 21; // MVN
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
-#if 0
case 0xe: // BIC - Rd:= Op1 AND NOT Op2
opcode = 0x0 << 21; // AND
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
-#endif
case 0xf: // MVN - Rd:= NOT Op2
opcode = 0xd << 21; // MOV
- operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
+ immediate_value = ~immediate_value;
break;
default:
tcc_error("cannot use '%s' with a negative immediate value",
get_tok_str(token, NULL));
}
+ for (half_immediate_rotation = 0; half_immediate_rotation < 16;
++half_immediate_rotation) {
+ if (immediate_value >= 0x00 && immediate_value < 0x100)
+ break;
+ // rotate left by two
+ immediate_value = ((immediate_value & 0x3FFFFFFF) << 2) |
((immediate_value & 0xC0000000) >> 30);
+ }
+ if (half_immediate_rotation >= 16) {
+ tcc_error("immediate value 0x%X cannot be encoded into ARM
immediate", (unsigned) immediate_value);
+ return;
+ }
+ operands |= immediate_value;
+ operands |= half_immediate_rotation << 8;
break;
default:
expect("(second source operand) register or immediate value");
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