diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 80 |
1 files changed, 78 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index a7556f438e5..1454d414f09 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -44,6 +44,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "config.h" #include "system.h" +#include "coretypes.h" +#include "tm.h" #include "flags.h" #include "tree.h" #include "real.h" @@ -5081,6 +5083,18 @@ fold (expr) } else if (TREE_CODE (arg0) == ABS_EXPR || TREE_CODE (arg0) == NEGATE_EXPR) return build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)); + else + { + /* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */ + enum built_in_function fcode = builtin_mathfn_code (arg0); + if (fcode == BUILT_IN_SQRT + || fcode == BUILT_IN_SQRTF + || fcode == BUILT_IN_SQRTL + || fcode == BUILT_IN_EXP + || fcode == BUILT_IN_EXPF + || fcode == BUILT_IN_EXPL) + t = arg0; + } return t; case CONJ_EXPR: @@ -5521,6 +5535,38 @@ fold (expr) tree arg = save_expr (arg0); return build (PLUS_EXPR, type, arg, arg); } + + if (flag_unsafe_math_optimizations) + { + enum built_in_function fcode0 = builtin_mathfn_code (arg0); + enum built_in_function fcode1 = builtin_mathfn_code (arg1); + + /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */ + if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT) + || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF) + || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL)) + { + tree sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0); + tree arg = build (MULT_EXPR, type, + TREE_VALUE (TREE_OPERAND (arg0, 1)), + TREE_VALUE (TREE_OPERAND (arg1, 1))); + tree arglist = build_tree_list (NULL_TREE, arg); + return fold (build_function_call_expr (sqrtfn, arglist)); + } + + /* Optimize exp(x)*exp(y) as exp(x+y). */ + if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP) + || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF) + || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL)) + { + tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0); + tree arg = build (PLUS_EXPR, type, + TREE_VALUE (TREE_OPERAND (arg0, 1)), + TREE_VALUE (TREE_OPERAND (arg1, 1))); + tree arglist = build_tree_list (NULL_TREE, arg); + return fold (build_function_call_expr (expfn, arglist)); + } + } } goto associate; @@ -5689,6 +5735,23 @@ fold (expr) TREE_OPERAND (arg1, 0)), TREE_OPERAND (arg1, 1))); } + + /* Optimize x/exp(y) into x*exp(-y). */ + if (flag_unsafe_math_optimizations) + { + enum built_in_function fcode = builtin_mathfn_code (arg1); + if (fcode == BUILT_IN_EXP + || fcode == BUILT_IN_EXPF + || fcode == BUILT_IN_EXPL) + { + tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0); + tree arg = build1 (NEGATE_EXPR, type, + TREE_VALUE (TREE_OPERAND (arg1, 1))); + tree arglist = build_tree_list (NULL_TREE, arg); + arg1 = build_function_call_expr (expfn, arglist); + return fold (build (MULT_EXPR, type, arg0, arg1)); + } + } goto binary; case TRUNC_DIV_EXPR: @@ -5734,12 +5797,25 @@ fold (expr) goto binary; - case LSHIFT_EXPR: - case RSHIFT_EXPR: case LROTATE_EXPR: case RROTATE_EXPR: + if (integer_all_onesp (arg0)) + return omit_one_operand (type, arg0, arg1); + goto shift; + + case RSHIFT_EXPR: + /* Optimize -1 >> x for arithmetic right shifts. */ + if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type)) + return omit_one_operand (type, arg0, arg1); + /* ... fall through ... */ + + case LSHIFT_EXPR: + shift: if (integer_zerop (arg1)) return non_lvalue (convert (type, arg0)); + if (integer_zerop (arg0)) + return omit_one_operand (type, arg0, arg1); + /* Since negative shift count is not well-defined, don't try to compute it in the compiler. */ if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0) |