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Compile negated conditions as inverted jumps #23292

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30 changes: 26 additions & 4 deletions Zend/zend_compile.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2432,6 +2432,20 @@ static inline uint32_t zend_emit_cond_jump(uint8_t opcode, znode *cond, uint32_t
}
/* }}} */

/* Compile `!` in a condition as an inverted jump instead of a BOOL_NOT
* opcode followed by a jump. Both evaluate the operand with the same
* boolean semantics, and removing the intermediate temporary also lets
* comparisons fuse with the jump (smart branch). */
static zend_ast *zend_unwrap_bool_not(zend_ast *cond_ast, uint8_t *jump_opcode) /* {{{ */
{
while (cond_ast->kind == ZEND_AST_UNARY_OP && cond_ast->attr == ZEND_BOOL_NOT) {
*jump_opcode = (*jump_opcode == ZEND_JMPZ) ? ZEND_JMPNZ : ZEND_JMPZ;
cond_ast = cond_ast->child[0];
}
return cond_ast;
}
/* }}} */

static inline void zend_update_jump_target(uint32_t opnum_jump, uint32_t opnum_target) /* {{{ */
{
zend_op *opline = &CG(active_op_array)->opcodes[opnum_jump];
Expand Down Expand Up @@ -6448,9 +6462,11 @@ static void zend_compile_while(const zend_ast *ast) /* {{{ */

opnum_cond = get_next_op_number();
zend_update_jump_target(opnum_jmp, opnum_cond);
uint8_t jump_opcode = ZEND_JMPNZ;
cond_ast = zend_unwrap_bool_not(cond_ast, &jump_opcode);
zend_compile_expr(&cond_node, cond_ast);

zend_emit_cond_jump(ZEND_JMPNZ, &cond_node, opnum_start);
zend_emit_cond_jump(jump_opcode, &cond_node, opnum_start);

zend_end_loop(opnum_cond, NULL);
}
Expand All @@ -6470,9 +6486,11 @@ static void zend_compile_do_while(const zend_ast *ast) /* {{{ */
zend_compile_stmt(stmt_ast);

opnum_cond = get_next_op_number();
uint8_t jump_opcode = ZEND_JMPNZ;
cond_ast = zend_unwrap_bool_not(cond_ast, &jump_opcode);
zend_compile_expr(&cond_node, cond_ast);

zend_emit_cond_jump(ZEND_JMPNZ, &cond_node, opnum_start);
zend_emit_cond_jump(jump_opcode, &cond_node, opnum_start);

zend_end_loop(opnum_cond, NULL);
}
Expand Down Expand Up @@ -6661,8 +6679,10 @@ static void zend_compile_if(zend_ast *ast) /* {{{ */
zend_do_extended_stmt(NULL);
}

uint8_t jump_opcode = ZEND_JMPZ;
cond_ast = zend_unwrap_bool_not(cond_ast, &jump_opcode);
zend_compile_expr(&cond_node, cond_ast);
opnum_jmpz = zend_emit_cond_jump(ZEND_JMPZ, &cond_node, 0);
opnum_jmpz = zend_emit_cond_jump(jump_opcode, &cond_node, 0);

zend_compile_stmt(stmt_ast);

Expand Down Expand Up @@ -11128,9 +11148,11 @@ static void zend_compile_conditional(znode *result, zend_ast *ast) /* {{{ */
return;
}

uint8_t jump_opcode = ZEND_JMPZ;
cond_ast = zend_unwrap_bool_not(cond_ast, &jump_opcode);
zend_compile_expr(&cond_node, cond_ast);

opnum_jmpz = zend_emit_cond_jump(ZEND_JMPZ, &cond_node, 0);
opnum_jmpz = zend_emit_cond_jump(jump_opcode, &cond_node, 0);

zend_compile_expr(&true_node, true_ast);

Expand Down
10 changes: 5 additions & 5 deletions ext/opcache/tests/opt/gh18107_1.phpt
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Original file line number Diff line number Diff line change
Expand Up @@ -29,16 +29,16 @@ $_main:
; %s
0000 T1 = ISSET_ISEMPTY_CV (isset) CV0($badvar)
0001 JMPNZ T1 0006
0002 T3 = NEW 1 string("Exception")
0002 T2 = NEW 1 string("Exception")
0003 SEND_VAL%S string("Should happen") 1
0004 DO_FCALL
0005 THROW T3
0005 THROW T2
0006 JMP 0006
0007 T6 = NEW 1 string("Exception")
0007 T5 = NEW 1 string("Exception")
0008 SEND_VAL%S string("Should not happen") 1
0009 DO_FCALL
0010 THROW T6
0011 FAST_RET T5
0010 THROW T5
0011 FAST_RET T4
EXCEPTION TABLE:
0006, -, 0007, 0011

Expand Down
12 changes: 6 additions & 6 deletions ext/opcache/tests/opt/gh18107_2.phpt
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Original file line number Diff line number Diff line change
Expand Up @@ -32,19 +32,19 @@ $_main:
; %s
0000 T2 = ISSET_ISEMPTY_CV (isset) CV0($badvar)
0001 JMPNZ T2 0008
0002 T4 = NEW 1 string("Exception")
0002 T3 = NEW 1 string("Exception")
0003 SEND_VAL%S string("Should happen") 1
0004 DO_FCALL
0005 THROW T4
0005 THROW T3
0006 CV1($e) = CATCH string("Throwable")
0007 ECHO string("foo")
0008 T6 = FAST_CALL 0010
0008 T5 = FAST_CALL 0010
0009 JMP 0015
0010 T7 = NEW 1 string("Exception")
0010 T6 = NEW 1 string("Exception")
0011 SEND_VAL%S string("Should not happen") 1
0012 DO_FCALL
0013 THROW T7
0014 FAST_RET T6
0013 THROW T6
0014 FAST_RET T5
0015 RETURN int(1)
EXCEPTION TABLE:
0006, 0006, 0010, 0014
Expand Down
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