From: Christoph Mallon <christoph.mallon@gmx.de>
Date: Tue, 24 Jun 2008 18:08:48 +0000 (+0000)
Subject: Add ARM TstBra and use it for comparison with 0.
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;ds=sidebyside;h=dc109198dce6364827389be03e29e8f920aaf2c8;p=libfirm

Add ARM TstBra and use it for comparison with 0.

[r20246]
---

diff --git a/ir/be/arm/arm_emitter.c b/ir/be/arm/arm_emitter.c
index 7c7b809f9..6ce78d3c7 100644
--- a/ir/be/arm/arm_emitter.c
+++ b/ir/be/arm/arm_emitter.c
@@ -453,6 +453,80 @@ static void emit_arm_CmpBra(const ir_node *irn) {
 	}
 }
 
+
+/**
+ * Emit a Tst with conditional branch.
+ */
+static void emit_arm_TstBra(const ir_node *irn)
+{
+	const ir_edge_t *edge;
+	const ir_node *proj_true  = NULL;
+	const ir_node *proj_false = NULL;
+	const ir_node *block;
+	const ir_node *next_block;
+	const char *suffix;
+	int proj_num = get_arm_CondJmp_proj_num(irn);
+
+	foreach_out_edge(irn, edge) {
+		ir_node *proj = get_edge_src_irn(edge);
+		long nr = get_Proj_proj(proj);
+		if (nr == pn_Cond_true) {
+			proj_true = proj;
+		} else {
+			proj_false = proj;
+		}
+	}
+
+	/* for now, the code works for scheduled and non-schedules blocks */
+	block = get_nodes_block(irn);
+
+	/* we have a block schedule */
+	next_block = sched_next_block(block);
+
+	assert(proj_num != pn_Cmp_False);
+	assert(proj_num != pn_Cmp_True);
+
+	if (get_cfop_target_block(proj_true) == next_block) {
+		/* exchange both proj's so the second one can be omitted */
+		const ir_node *t = proj_true;
+
+		proj_true  = proj_false;
+		proj_false = t;
+		proj_num   = get_negated_pnc(proj_num, mode_Iu);
+	}
+	switch (proj_num) {
+		case pn_Cmp_Eq:  suffix = "eq"; break;
+		case pn_Cmp_Lt:  suffix = "lt"; break;
+		case pn_Cmp_Le:  suffix = "le"; break;
+		case pn_Cmp_Gt:  suffix = "gt"; break;
+		case pn_Cmp_Ge:  suffix = "ge"; break;
+		case pn_Cmp_Lg:  suffix = "ne"; break;
+		case pn_Cmp_Leg: suffix = "al"; break;
+		default: assert(!"Cmp unsupported"); suffix = "al";
+	}
+	be_emit_cstring("\ttst ");
+	arm_emit_source_register(irn, 0);
+	be_emit_cstring(", ");
+	arm_emit_source_register(irn, 1);
+	be_emit_finish_line_gas(irn);
+
+	/* emit the true proj */
+	be_emit_irprintf("\tb%s ", suffix);
+	arm_emit_cfop_target(proj_true);
+	be_emit_finish_line_gas(proj_true);
+
+	if (get_cfop_target_block(proj_false) == next_block) {
+		be_emit_cstring("\t/* fallthrough to ");
+		arm_emit_cfop_target(proj_false);
+		be_emit_cstring(" */");
+		be_emit_finish_line_gas(proj_false);
+	} else {
+		be_emit_cstring("b ");
+		arm_emit_cfop_target(proj_false);
+		be_emit_finish_line_gas(proj_false);
+	}
+}
+
 /**
  * Emit a Compare with conditional branch.
  */
@@ -945,6 +1019,7 @@ static void arm_register_emitters(void) {
 
 	/* other emitter functions */
 	ARM_EMIT(CmpBra);
+	ARM_EMIT(TstBra);
 	ARM_EMIT(fpaCmfBra);
 	ARM_EMIT(fpaCmfeBra);
 	ARM_EMIT(CopyB);
diff --git a/ir/be/arm/arm_spec.pl b/ir/be/arm/arm_spec.pl
index 5c9fe4e3c..a17d473d8 100644
--- a/ir/be/arm/arm_spec.pl
+++ b/ir/be/arm/arm_spec.pl
@@ -578,6 +578,17 @@ CmpBra => {
 	attr_type => "arm_CondJmp_attr_t",
 },
 
+TstBra => {
+	op_flags  => "L|X|Y",
+	state     => "pinned",
+	comment   => "construct conditional branch: TST A, B && JMPxx LABEL",
+	mode      => "mode_T",
+	attr      => "int proj_num",
+	init_attr => "\tset_arm_CondJmp_proj_num(res, proj_num);",
+	reg_req   => { "in" => [ "gp", "gp" ], "out" => [ "none", "none"] },
+	attr_type => "arm_CondJmp_attr_t",
+},
+
 SwitchJmp => {
 	op_flags  => "L|X|Y",
 	state     => "pinned",
diff --git a/ir/be/arm/arm_transform.c b/ir/be/arm/arm_transform.c
index 2be1c7b78..27e805ce9 100644
--- a/ir/be/arm/arm_transform.c
+++ b/ir/be/arm/arm_transform.c
@@ -935,9 +935,9 @@ static ir_node *gen_Cond(ir_node *node) {
 		ir_node *op1      = get_Cmp_left(cmp_node);
 		ir_node *new_op1  = be_transform_node(op1);
 		ir_node *op2      = get_Cmp_right(cmp_node);
-		ir_node *new_op2  = be_transform_node(op2);
 
 		if (mode_is_float(get_irn_mode(op1))) {
+			ir_node *new_op2  = be_transform_node(op2);
 			/* floating point compare */
 			pn_Cmp pnc = get_Proj_proj(selector);
 
@@ -947,8 +947,12 @@ static ir_node *gen_Cond(ir_node *node) {
 			}
 			/* Hmm: use need cmfe */
 			return new_rd_arm_fpaCmfeBra(dbg, irg, block, new_op1, new_op2, pnc);
+		} else if (is_Const(op2) && tarval_is_null(get_Const_tarval(op2))) {
+			/* compare with 0 */
+			return new_rd_arm_TstBra(dbg, irg, block, new_op1, new_op1, get_Proj_proj(selector));
 		} else {
 			/* integer compare */
+			ir_node *new_op2  = be_transform_node(op2);
 			return new_rd_arm_CmpBra(dbg, irg, block, new_op1, new_op2, get_Proj_proj(selector));
 		}
 	} else {