only construct Rotl if backend supports it

[r27953]

include/libfirm/be.h

@@ -73,6 +73,8 @@ typedef void (*lower_for_target_func)(void);
 typedef struct backend_params {
 	/** If set, the backend supports inline assembly. */
 	unsigned support_inline_asm:1;
+	/** If set, the backend supports Rotl nodes */
+	unsigned support_rotl:1;
 
 	/** callback that performs lowerings required for target architecture */
 	lower_for_target_func lower_for_target;

include/libfirm/irarch.h

@@ -60,7 +60,7 @@ typedef int (*evaluate_costs_func)(insn_kind kind, tarval *tv);
 struct ir_settings_arch_dep_t {
 	/* Mul optimization */
 	unsigned also_use_subs : 1;    /**< Use also Subs when resolving Muls to shifts */
-	unsigned maximum_shifts;            /**< The maximum number of shifts that shall be inserted for a mul. */
+	unsigned maximum_shifts;       /**< The maximum number of shifts that shall be inserted for a mul. */
 	unsigned highest_shift_amount; /**< The highest shift amount you want to
 	                                    tolerate. Muls which would require a higher
 	                                    shift constant are left. */
@@ -69,7 +69,7 @@ struct ir_settings_arch_dep_t {
 	/* Div/Mod optimization */
 	unsigned allow_mulhs   : 1;    /**< Use the Mulhs operation for division by constant */
 	unsigned allow_mulhu   : 1;    /**< Use the Mulhu operation for division by constant */
-	unsigned max_bits_for_mulh;         /**< Maximum number of bits the Mulh operation can take.
+	unsigned max_bits_for_mulh;    /**< Maximum number of bits the Mulh operation can take.
 	                                    Modes with higher amount of bits will use Mulh */
 };
 

ir/be/TEMPLATE/bearch_TEMPLATE.c

@@ -454,6 +454,7 @@ static const backend_params *TEMPLATE_get_backend_params(void)
 {
 	static backend_params p = {
 		0,     /* no inline assembly */
+		0,     /* no support for Rotl nodes */
 		TEMPLATE_lower_for_target,  /* lowering for target */
 		NULL,  /* architecture dependent settings, will be set later */
 		NULL,  /* parameter for if conversion */

ir/be/amd64/bearch_amd64.c

@@ -611,6 +611,7 @@ static void amd64_lower_for_target(void)
 static const backend_params *amd64_get_backend_params(void) {
 	static backend_params p = {
 		0,     /* no inline assembly */
+		1,     /* support Rotl nodes */
 		amd64_lower_for_target,  /* lowering callback */
 		NULL,  /* will be set later */
 		NULL,  /* parameter for if conversion */

ir/be/arm/bearch_arm.c

@@ -691,6 +691,7 @@ static const backend_params *arm_get_libfirm_params(void)
 	};
 	static backend_params p = {
 		0,     /* don't support inline assembler yet */
+		1,     /* support Rotl nodes */
 		NULL,  /* lowering function */
 		&ad,   /* will be set later */
 		arm_is_mux_allowed, /* allow_ifconv function */

ir/be/bemain.c

@@ -343,6 +343,7 @@ int be_parse_arg(const char *arg)
 /** The be parameters returned by default, all off. */
 static const backend_params be_params = {
 	0,    /* don't support inline assembler yet */
+	0,    /* don't support rotl */
 	NULL, /* no lowering required */
 	NULL, /* will be set later */
 	NULL, /* no if conversion settings */

ir/be/ia32/bearch_ia32.c

@@ -2394,6 +2394,7 @@ static const backend_params *ia32_get_libfirm_params(void)
 	};
 	static backend_params p = {
 		1,     /* support inline assembly */
+		1,     /* support Rotl nodes */
 		ia32_lower_for_target,
 		NULL,  /* will be set later */
 		ia32_is_mux_allowed,

ir/be/sparc/bearch_sparc.c

@@ -572,6 +572,7 @@ static const backend_params *sparc_get_backend_params(void)
 {
 	static backend_params p = {
 		0,     /* no inline assembly */
+		0,     /* no support for RotL nodes */
 		sparc_lower_for_target, /* lowering callback */
 		NULL,  /* will be set later */
 		NULL,  /* parameter for if conversion */

ir/ir/iropt.c

@@ -50,6 +50,7 @@
 #include "array_t.h"
 #include "vrp.h"
 #include "firm_types.h"
+#include "be.h"
 
 /* Make types visible to allow most efficient access */
 #include "entity_t.h"
@@ -5165,6 +5166,10 @@ static ir_node *transform_node_Or_Rotl(ir_node *or)
 				!= (int) get_mode_size_bits(mode))
 			return or;
 
+		/* some backends can't handle rotl */
+		if (!be_get_backend_param()->support_rotl)
+			return or;
+
 		/* yet, condition met */
 		block = get_nodes_block(or);
 
@@ -5180,9 +5185,11 @@ static ir_node *transform_node_Or_Rotl(ir_node *or)
         rotval = sub; /* a Rot right is not supported, so use a rot left */
     } else if (is_Sub(c2)) {
 		v      = c1;
-    	sub    = c2;
+		sub    = c2;
         rotval = v;
-    } else return or;
+    } else {
+		return or;
+	}
 
 	if (get_Sub_right(sub) != v)
 		return or;
@@ -5198,6 +5205,10 @@ static ir_node *transform_node_Or_Rotl(ir_node *or)
 	if (get_tarval_long(tv1) != (int) get_mode_size_bits(mode))
 		return or;
 
+	/* some backends can't handle rotl */
+	if (!be_get_backend_param()->support_rotl)
+		return or;
+
 	/* yet, condition met */
 	block = get_nodes_block(or);