From: Nikita Popov <nikic@php.net>
Date: Sat, 9 Jan 2016 17:42:07 +0000 (+0100)
Subject: Add support for Pi type constraints
X-Git-Tag: php-7.2.0alpha1~620^2~102
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5662d73528f7be103c8812b97dc239957c1f4626;p=php

Add support for Pi type constraints

Supports TYPE_CHECK and IS_IDENTICAL for now.
---

diff --git a/ext/opcache/Optimizer/zend_dump.c b/ext/opcache/Optimizer/zend_dump.c
index fddc5a9741..46952c1159 100644
--- a/ext/opcache/Optimizer/zend_dump.c
+++ b/ext/opcache/Optimizer/zend_dump.c
@@ -305,8 +305,14 @@ void zend_dump_ssa_var(const zend_op_array *op_array, const zend_ssa *ssa, int s
 	}
 }
 
-static void zend_dump_pi_range(const zend_op_array *op_array, const zend_ssa *ssa, const zend_ssa_pi_range *r)
+static void zend_dump_pi_constraint(const zend_op_array *op_array, const zend_ssa *ssa, const zend_ssa_pi_constraint *r)
 {
+	if (r->type_mask != (uint32_t) -1) {
+		fprintf(stderr, " TYPE");
+		zend_dump_type_info(r->type_mask, NULL, 0);
+		return;
+	}
+
 	if (r->range.underflow && r->range.overflow) {
 		return;
 	}
@@ -791,7 +797,7 @@ static void zend_dump_block_header(const zend_cfg *cfg, const zend_op_array *op_
 				fprintf(stderr, " = Pi(");
 				zend_dump_ssa_var(op_array, ssa, p->sources[0], 0, p->var);
 				fprintf(stderr, " &");
-				zend_dump_pi_range(op_array, ssa, &p->constraint);
+				zend_dump_pi_constraint(op_array, ssa, &p->constraint);
 				fprintf(stderr, ")\n");
 			}
 			p = p->next;
diff --git a/ext/opcache/Optimizer/zend_inference.c b/ext/opcache/Optimizer/zend_inference.c
index 2ff9727254..beec91924c 100644
--- a/ext/opcache/Optimizer/zend_inference.c
+++ b/ext/opcache/Optimizer/zend_inference.c
@@ -475,7 +475,7 @@ int zend_inference_calc_range(const zend_op_array *op_array, zend_ssa *ssa, int
 		tmp->min = ZEND_LONG_MAX;
 		tmp->max = ZEND_LONG_MIN;
 		tmp->overflow = 0;
-		if (p->pi >= 0) {
+		if (p->pi >= 0 && p->constraint.type_mask == (uint32_t) -1) {
 			if (p->constraint.negative) {
 				if (ssa->var_info[p->sources[0]].has_range) {
 					tmp->underflow = ssa->var_info[p->sources[0]].range.underflow;
@@ -1814,6 +1814,7 @@ static void zend_infer_ranges_warmup(const zend_op_array *op_array, zend_ssa *ss
 				    ssa->var_info[j].has_range &&
 				    ssa->vars[j].definition_phi &&
 				    ssa->vars[j].definition_phi->pi >= 0 &&
+				    ssa->vars[j].definition_phi->constraint.type_mask == (uint32_t) -1 &&
 				    ssa->vars[j].definition_phi->constraint.negative &&
 				    ssa->vars[j].definition_phi->constraint.min_ssa_var < 0 &&
 				    ssa->vars[j].definition_phi->constraint.min_ssa_var < 0) {
@@ -3658,6 +3659,9 @@ int zend_infer_types_ex(const zend_op_array *op_array, const zend_script *script
 			zend_ssa_phi *p = ssa_vars[j].definition_phi;
 			if (p->pi >= 0) {
 				tmp = get_ssa_var_info(ssa, p->sources[0]);
+				if (p->constraint.type_mask != (uint32_t) -1) {
+					tmp &= p->constraint.type_mask;
+				}
 				UPDATE_SSA_TYPE(tmp, j);
 				if (ssa_var_info[p->sources[0]].ce) {
 					UPDATE_SSA_OBJ_TYPE(ssa_var_info[p->sources[0]].ce, ssa_var_info[p->sources[0]].is_instanceof, j);
diff --git a/ext/opcache/Optimizer/zend_ssa.c b/ext/opcache/Optimizer/zend_ssa.c
index 059550b63d..16d22dd258 100644
--- a/ext/opcache/Optimizer/zend_ssa.c
+++ b/ext/opcache/Optimizer/zend_ssa.c
@@ -21,6 +21,7 @@
 #include "zend_dfg.h"
 #include "zend_ssa.h"
 #include "zend_dump.h"
+#include "zend_inference.h"
 
 static int needs_pi(const zend_op_array *op_array, zend_dfg *dfg, zend_ssa *ssa, int from, int to, int var) /* {{{ */
 {
@@ -78,6 +79,7 @@ static void pi_range(
 	phi->constraint.range.underflow = underflow;
 	phi->constraint.range.overflow = overflow;
 	phi->constraint.negative = negative ? NEG_INIT : NEG_NONE;
+	phi->constraint.type_mask = (uint32_t) -1;
 }
 /* }}} */
 
@@ -94,6 +96,27 @@ static inline void pi_range_max(zend_ssa_phi *phi, int var, zend_long val) {
 	pi_range(phi, -1, var, ZEND_LONG_MIN, val, 1, 0, 0);
 }
 
+static void pi_type_mask(zend_ssa_phi *phi, uint32_t type_mask) {
+	phi->constraint.type_mask = MAY_BE_REF|MAY_BE_RC1|MAY_BE_RCN;
+	phi->constraint.type_mask |= type_mask;
+	if (type_mask & MAY_BE_NULL) {
+		phi->constraint.type_mask |= MAY_BE_UNDEF;
+	}
+}
+static inline void pi_not_type_mask(zend_ssa_phi *phi, uint32_t type_mask) {
+	uint32_t relevant = MAY_BE_ANY|MAY_BE_ARRAY_KEY_ANY|MAY_BE_ARRAY_OF_ANY|MAY_BE_ARRAY_OF_REF;
+	pi_type_mask(phi, ~type_mask & relevant);
+}
+static inline uint32_t mask_for_type_check(uint32_t type) {
+	if (type == _IS_BOOL) {
+		return MAY_BE_TRUE|MAY_BE_FALSE;
+	} else if (type == IS_ARRAY) {
+		return MAY_BE_ARRAY|MAY_BE_ARRAY_KEY_ANY|MAY_BE_ARRAY_OF_ANY|MAY_BE_ARRAY_OF_REF;
+	} else {
+		return 1 << type;
+	}
+}
+
 /* We can interpret $a + 5 == 0 as $a = 0 - 5, i.e. shift the adjustment to the other operand.
  * This negated adjustment is what is written into the "adjustment" parameter. */
 static int find_adjusted_tmp_var(const zend_op_array *op_array, uint32_t build_flags, zend_op *opline, uint32_t var_num, zend_long *adjustment)
@@ -805,6 +828,59 @@ int zend_build_ssa(zend_arena **arena, const zend_op_array *op_array, uint32_t b
 			if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bt, var))) {
 				pi_range_not_equals(pi, -1, 0);
 			}
+		} else if (opline->op1_type == IS_TMP_VAR && (opline-1)->opcode == ZEND_TYPE_CHECK &&
+				   opline->op1.var == (opline-1)->result.var && (opline-1)->op1_type == IS_CV) {
+			int var = EX_VAR_TO_NUM((opline-1)->op1.var);
+			uint32_t type = (opline-1)->extended_value;
+			if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bt, var))) {
+				pi_type_mask(pi, mask_for_type_check(type));
+			}
+			if (type != IS_OBJECT && type != IS_RESOURCE) {
+				/* is_object() and is_resource() may return false, even though the value is
+				 * an object/resource. */
+				if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bf, var))) {
+					pi_not_type_mask(pi, mask_for_type_check(type));
+				}
+			}
+		} else if (opline->op1_type == IS_TMP_VAR &&
+				   ((opline-1)->opcode == ZEND_IS_IDENTICAL
+					|| (opline-1)->opcode == ZEND_IS_NOT_IDENTICAL) &&
+				   opline->op1.var == (opline-1)->result.var) {
+			int var;
+			zval *val;
+			uint32_t type_mask;
+			if ((opline-1)->op1_type == IS_CV && (opline-1)->op2_type == IS_CONST) {
+				var = EX_VAR_TO_NUM((opline-1)->op1.var);
+				val = CRT_CONSTANT((opline-1)->op2);
+			} else if ((opline-1)->op1_type == IS_CONST && (opline-1)->op2_type == IS_CV) {
+				var = EX_VAR_TO_NUM((opline-1)->op2.var);
+				val = CRT_CONSTANT((opline-1)->op1);
+			} else {
+				continue;
+			}
+
+			/* We're interested in === null/true/false comparisons here, because they eliminate
+			 * a type in the false-branch. Other === VAL comparisons are unlikely to be useful. */
+			if (Z_TYPE_P(val) != IS_NULL && Z_TYPE_P(val) != IS_TRUE && Z_TYPE_P(val) != IS_FALSE) {
+				continue;
+			}
+
+			type_mask = _const_op_type(val);
+			if ((opline-1)->opcode == ZEND_IS_IDENTICAL) {
+				if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bt, var))) {
+					pi_type_mask(pi, type_mask);
+				}
+				if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bf, var))) {
+					pi_not_type_mask(pi, type_mask);
+				}
+			} else {
+				if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bf, var))) {
+					pi_type_mask(pi, type_mask);
+				}
+				if ((pi = add_pi(arena, op_array, &dfg, ssa, j, bt, var))) {
+					pi_not_type_mask(pi, type_mask);
+				}
+			}
 		}
 	}
 
diff --git a/ext/opcache/Optimizer/zend_ssa.h b/ext/opcache/Optimizer/zend_ssa.h
index 0e1bc84dbc..00d6875dfd 100644
--- a/ext/opcache/Optimizer/zend_ssa.h
+++ b/ext/opcache/Optimizer/zend_ssa.h
@@ -38,21 +38,22 @@ typedef enum _zend_ssa_negative_lat {
 } zend_ssa_negative_lat;
 
 /* Special kind of SSA Phi function used in eSSA */
-typedef struct _zend_ssa_pi_range {
+typedef struct _zend_ssa_pi_constraint {
 	zend_ssa_range         range;       /* simple range constraint */
 	int                    min_var;
 	int                    max_var;
 	int                    min_ssa_var; /* ((min_var>0) ? MIN(ssa_var) : 0) + range.min */
 	int                    max_ssa_var; /* ((man_var>0) ? MAX(ssa_var) : 0) + range.man */
 	zend_ssa_negative_lat  negative;
-} zend_ssa_pi_range;
+	uint32_t               type_mask;   /* If -1 this is a range constraint */
+} zend_ssa_pi_constraint;
 
 /* SSA Phi - ssa_var = Phi(source0, source1, ...sourceN) */
 typedef struct _zend_ssa_phi zend_ssa_phi;
 struct _zend_ssa_phi {
 	zend_ssa_phi          *next;          /* next Phi in the same BB */
 	int                    pi;            /* if >= 0 this is actually a e-SSA Pi */
-	zend_ssa_pi_range      constraint;    /* e-SSA Pi constraint */
+	zend_ssa_pi_constraint constraint;    /* e-SSA Pi constraint */
 	int                    var;           /* Original CV, VAR or TMP variable index */
 	int                    ssa_var;       /* SSA variable index */
 	int                    block;         /* current BB index */