assembler/bdw: Set jip/uip offsets used by flow control instructions

Signed-off-by: Xiang, Haihao <haihao.xiang@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

2 files changed, 88 insertions, 47 deletions

diff --git a/assembler/gram.y b/assembler/gram.y
index a603c2c2..f8483d3d 100644
--- a/assembler/gram.y
+++ b/assembler/gram.y
@@ -117,6 +117,9 @@ static void set_direct_dst_operand(struct brw_reg *dst, struct brw_reg *reg,
 static void set_direct_src_operand(struct src_operand *src, struct brw_reg *reg,
 				   int type);
 
+void set_branch_two_offsets(struct brw_program_instruction *insn, int jip_offset, int uip_offset);
+void set_branch_one_offset(struct brw_program_instruction *insn, int jip_offset);
+
 enum message_level {
     WARN,
     ERROR,
@@ -3152,3 +3155,83 @@ static void set_direct_src_operand(struct src_operand *src, struct brw_reg *reg,
 	src->reg.abs = 0;
 	SWIZZLE(src->reg) = BRW_SWIZZLE_NOOP;
 }
+
+static inline int instruction_opcode(struct brw_program_instruction *insn)
+{
+    if (IS_GENp(8))
+	return gen8_opcode(GEN8(insn));
+    else
+	return GEN(insn)->header.opcode;
+}
+
+/*
+ * return the offset used in native flow control (branch) instructions
+ */
+static inline int branch_offset(struct brw_program_instruction *insn, int offset)
+{
+    /*
+     * bspec: Unlike other flow control instructions, the offset used by JMPI
+     * is relative to the incremented instruction pointer rather than the IP
+     * value for the instruction itself.
+     */
+    if (instruction_opcode(insn) == BRW_OPCODE_JMPI)
+        offset--;
+
+    /*
+     * Gen4- bspec: the jump distance is in number of sixteen-byte units
+     * Gen5+ bspec: the jump distance is in number of eight-byte units
+     * Gen7.5+: the offset is in unit of 8bits for JMPI, 64bits for other flow
+     * control instructions
+     */
+    if (gen_level >= 75 &&
+        (instruction_opcode(insn) == BRW_OPCODE_JMPI))
+        offset *= 16;
+    else if (gen_level >= 50)
+        offset *= 2;
+
+    return offset;
+}
+
+void set_branch_two_offsets(struct brw_program_instruction *insn, int jip_offset, int uip_offset)
+{
+    int jip = branch_offset(insn, jip_offset);
+    int uip = branch_offset(insn, uip_offset);
+
+    assert(instruction_opcode(insn) != BRW_OPCODE_JMPI);
+
+    if (IS_GENp(8)) {
+        gen8_set_jip(GEN8(insn), jip);
+	gen8_set_uip(GEN8(insn), uip);
+    } else {
+        GEN(insn)->bits3.break_cont.jip = jip;
+        GEN(insn)->bits3.break_cont.uip = uip;
+    }
+}
+
+void set_branch_one_offset(struct brw_program_instruction *insn, int jip_offset)
+{
+    int jip = branch_offset(insn, jip_offset);
+
+    if (IS_GENp(8)) {
+        gen8_set_jip(GEN8(insn), jip);
+    } else if (IS_GENx(7)) {
+        /* Gen7 JMPI Restrictions in bspec:
+         * The JIP data type must be Signed DWord
+         */
+        if (instruction_opcode(insn) == BRW_OPCODE_JMPI)
+            GEN(insn)->bits3.JIP = jip;
+        else
+            GEN(insn)->bits3.break_cont.jip = jip;
+    } else if (IS_GENx(6)) {
+        if ((instruction_opcode(insn) == BRW_OPCODE_CALL) ||
+            (instruction_opcode(insn) == BRW_OPCODE_JMPI))
+            GEN(insn)->bits3.JIP = jip;
+        else
+            GEN(insn)->bits1.branch_gen6.jump_count = jip; // for CASE,ELSE,FORK,IF,WHILE
+    } else {
+        GEN(insn)->bits3.JIP = jip;
+
+        if (instruction_opcode(insn) == BRW_OPCODE_ELSE)
+            GEN(insn)->bits3.break_cont.uip = 1; // Set the istack pop count, which must always be 1.
+    }
+}
diff --git a/assembler/main.c b/assembler/main.c
index 809977bc..469406ae 100644
--- a/assembler/main.c
+++ b/assembler/main.c
@@ -38,6 +38,8 @@
 #include "brw_eu.h"
 
 extern FILE *yyin;
+extern void set_branch_two_offsets(struct brw_program_instruction *insn, int jip_offset, int uip_offset);
+extern void set_branch_one_offset(struct brw_program_instruction *insn, int jip_offset);
 
 long int gen_level = 40;
 int advanced_flag = 0; /* 0: in unit of byte, 1: in unit of data element size */
@@ -86,16 +88,6 @@ static const struct option longopts[] = {
 	{ NULL, 0, NULL, 0 }
 };
 
-// jump distance used in branch instructions as JIP or UIP
-static int jump_distance(int offset)
-{
-    // Gen4- bspec: the jump distance is in number of sixteen-byte units
-    // Gen5+ bspec: the jump distance is in number of eight-byte units
-    if(IS_GENp(5))
-        offset *= 2;
-    return offset;
-}
-
 static void usage(void)
 {
 	fprintf(stderr, "usage: intel-gen4asm [options] inputfile\n");
@@ -438,7 +430,6 @@ int main(int argc, char **argv)
 
 	for (entry = compiled_program.first; entry; entry = entry->next) {
 	    struct relocation *reloc = &entry->reloc;
-	    struct brw_instruction *inst = &entry->insn.gen;
 
 	    if (!is_relocatable(entry))
 		continue;
@@ -449,43 +440,10 @@ int main(int argc, char **argv)
 	    if (reloc->second_reloc_target)
 		reloc->second_reloc_offset = label_to_addr(reloc->second_reloc_target, entry->inst_offset) - entry->inst_offset;
 
-	    if (reloc->second_reloc_offset) {
-		// this is a branch instruction with two offset arguments
-		inst->bits3.break_cont.jip = jump_distance(reloc->first_reloc_offset);
-		inst->bits3.break_cont.uip = jump_distance(reloc->second_reloc_offset);
+	    if (reloc->second_reloc_offset) { // this is a branch instruction with two offset arguments
+                set_branch_two_offsets(entry, reloc->first_reloc_offset, reloc->second_reloc_offset);
 	    } else if (reloc->first_reloc_offset) {
-		// this is a branch instruction with one offset argument
-		int offset = reloc->first_reloc_offset;
-		/* bspec: Unlike other flow control instructions, the offset used by JMPI is relative to the incremented instruction pointer rather than the IP value for the instruction itself. */
-
-		int is_jmpi = inst->header.opcode == BRW_OPCODE_JMPI; // target relative to the post-incremented IP, so delta == 1 if JMPI
-		if(is_jmpi)
-		    offset --;
-		offset = jump_distance(offset);
-		if (is_jmpi && (gen_level == 75))
-			offset = offset * 8;
-
-		if(!IS_GENp(6)) {
-		    inst->bits3.JIP = offset;
-		    if(inst->header.opcode == BRW_OPCODE_ELSE)
-			inst->bits3.break_cont.uip = 1; /* Set the istack pop count, which must always be 1. */
-		} else if(IS_GENx(6)) {
-		    /* TODO: endif JIP pos is not in Gen6 spec. may be bits1 */
-		    int opcode = inst->header.opcode;
-		    if(opcode == BRW_OPCODE_CALL || opcode == BRW_OPCODE_JMPI)
-			inst->bits3.JIP = offset; // for CALL, JMPI
-		    else
-			inst->bits1.branch_gen6.jump_count = offset; // for CASE,ELSE,FORK,IF,WHILE
-		} else if(IS_GENp(7)) {
-		    int opcode = inst->header.opcode;
-		    /* Gen7 JMPI Restrictions in bspec:
-		     * The JIP data type must be Signed DWord
-		     */
-		    if(opcode == BRW_OPCODE_JMPI)
-			inst->bits3.JIP = offset;
-		    else
-			inst->bits3.break_cont.jip = offset;
-		}
+                set_branch_one_offset(entry, reloc->first_reloc_offset);
 	    }
 	}