From 221b83997a22fc2abc2282d90763e0435943021c Mon Sep 17 00:00:00 2001
From: Andrew Chambers <ac@acha.ninja>
Date: Tue, 19 Oct 2021 16:15:49 +1300
Subject: Remove special case for call.

---
 asm.peg  |  7 ++++---
 main.c   | 47 ++++++++++++++++-------------------------------
 minias.h | 12 +-----------
 parse.c  | 10 ++++++++++
 4 files changed, 31 insertions(+), 45 deletions(-)

diff --git a/asm.peg b/asm.peg
index 39c5d0e..089bfb2 100644
--- a/asm.peg
+++ b/asm.peg
@@ -134,11 +134,12 @@ instr =
 
 call = "call" 'q'? ws (
     '*' t:mem
-      { $$.call = (Call){ .kind = ASM_CALL, .target.indirect=internparsev(&t), .indirect=1 } ; }
+      { $$ = OPMEM({.w=0}, -1, 0xff, 0x02, t); }
   | '*' t:r64 
-      { $$.call = (Call){ .kind = ASM_CALL, .target.indirect=internparsev(&t), .indirect=1 } ; }
+      { $$ = OPREG({.w=0}, -1, 0xff, 0x02, t); }
   | t:value 
-      { $$.call = (Call){ .kind = ASM_CALL, .target.direct=t.value, .indirect=0 } ; }
+      { Parsev ma = (Parsev){.memarg = (Memarg) {.kind=ASM_MEMARG, .disp = t.value }};
+        $$ = RELCALL({.w=0}, -1, 0xe8, ma); }
 )
 
 jmp = 'j' v:jmp-variant ws t:ident
diff --git a/main.c b/main.c
index f12ece5..8713b0c 100644
--- a/main.c
+++ b/main.c
@@ -480,30 +480,6 @@ assemblemem(const Memarg* memarg, Rex rex, VarBytes prefix, VarBytes opcode,
     }
 }
 
-static void
-assemblecall(const Call* call)
-{
-    Rex rex;
-    uint8_t rm;
-
-    if (call->indirect) {
-        if (call->target.indirect->kind == ASM_MEMARG) {
-            rex = (Rex){0};
-            assemblemem(&call->target.indirect->memarg, rex, -1, 0xff, 0x02, 0);
-        } else {
-            rm = regbits(call->target.indirect->kind);
-            rex = (Rex){ .b = !!(rm & (1 << 3)) };
-            assemblerex(rex);
-            assemblevbytes(0xff);
-            sb(modregrmbyte(0x03, 0x02, rm));
-        }
-    } else {
-        sb(0xe8);
-        assemblereloc(
-            call->target.direct.l, call->target.direct.c - 4, 4, R_X86_64_PC32);
-    }
-}
-
 static void
 assemblejmp(const Jmp* j)
 {
@@ -550,16 +526,20 @@ assemblejmp(const Jmp* j)
 static void
 assembleabsimm(const Imm* imm)
 {
+    int reltype;
+
     if (imm->nbytes == 1)
-        assemblereloc(imm->v.l, imm->v.c, imm->nbytes, R_X86_64_8);
+        reltype = R_X86_64_8;
     else if (imm->nbytes == 2)
-        assemblereloc(imm->v.l, imm->v.c, imm->nbytes, R_X86_64_16);
+        reltype = R_X86_64_16;
     else if (imm->nbytes == 4)
-        assemblereloc(imm->v.l, imm->v.c, imm->nbytes, R_X86_64_32);
+        reltype = R_X86_64_32;
     else if (imm->nbytes == 8)
-        assemblereloc(imm->v.l, imm->v.c, imm->nbytes, R_X86_64_64);
+        reltype = R_X86_64_64;
     else
         unreachable();
+
+    assemblereloc(imm->v.l, imm->v.c, imm->nbytes, reltype);
 }
 
 static void
@@ -618,6 +598,14 @@ assembleinstr(const Instr* instr)
         assemblevbytes(instr->opcode);
         assembleabsimm(imm);
         break;
+    case ENCODER_RELCALL:
+        memarg = &instr->arg1->memarg;
+        rex = instr->rex;
+        assemblevbytes(instr->prefix);
+        assemblerex(rex);
+        assemblevbytes(instr->opcode);
+        assemblereloc(memarg->disp.l, memarg->disp.c - 4, 4, R_X86_64_PC32);
+        break;
     case ENCODER_IMMREG:
         imm = &instr->arg1->imm;
         reg = instr->fixedreg;
@@ -821,9 +809,6 @@ assemble(void)
         case ASM_INSTR:
             assembleinstr(&v->instr);
             break;
-        case ASM_CALL:
-            assemblecall(&v->call);
-            break;
         case ASM_JMP:
             assemblejmp(&v->jmp);
             break;
diff --git a/minias.h b/minias.h
index ec8f7cc..1baaf89 100644
--- a/minias.h
+++ b/minias.h
@@ -61,7 +61,6 @@ typedef enum {
     ASM_DIR_QUAD,
     ASM_DIR_BALIGN,
     // Instructions.
-    ASM_CALL,
     ASM_JMP,
     ASM_INSTR,
     // Registers, order matters.
@@ -237,15 +236,6 @@ typedef struct String {
 typedef String Ascii;
 typedef String Asciiz;
 
-typedef struct Call {
-    AsmKind kind;
-    uint32_t indirect;
-    union {
-        const Parsev* indirect;
-        Value direct;
-    } target;
-} Call;
-
 typedef struct Jmp {
     AsmKind kind;
     uint32_t cc; /* 0 means unconditional. */
@@ -267,6 +257,7 @@ typedef enum Encoder {
     ENCODER_OP,
     ENCODER_OPREG,
     ENCODER_OPMEM,
+    ENCODER_RELCALL,
     ENCODER_R,
     ENCODER_RIMM,
     ENCODER_IMM,
@@ -305,7 +296,6 @@ union Parsev {
     Asciiz asciiz;
     Memarg memarg;
     Instr instr;
-    Call call;
     Jmp jmp;
     Fill fill;
     Byte dirbyte;
diff --git a/parse.c b/parse.c
index 3137447..da01509 100644
--- a/parse.c
+++ b/parse.c
@@ -168,6 +168,16 @@ needsmovabs(Imm* imm)
         }                                                                      \
     }
 
+#define RELCALL(REX, PREFIX, OPCODE, A1)                                       \
+    (Parsev)                                                                   \
+    {                                                                          \
+        .instr = (Instr)                                                       \
+        {                                                                      \
+            .kind = ASM_INSTR, .encoder = ENCODER_RELCALL, .prefix = PREFIX,   \
+            .opcode = OPCODE, .rex = (Rex)REX, .arg1 = internparsev(&A1),      \
+        }                                                                      \
+    }
+
 #define IMMREG(REX, PREFIX, OPCODE, IMMREG, A1, A2)                            \
     (Parsev)                                                                   \
     {                                                                          \
-- 
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