| Message ID | 87k1wyhr9a.fsf@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add tree_fits_uhwi_p tests to BIT_FIELD_REF folder | expand |
On 01/04/2018 03:06 AM, Richard Sandiford wrote: > The first BIT_FIELD_REF folding pattern assumed without checking that > operands satisfy tree_fits_uhwi_p. The second pattern does check this: > > /* On constants we can use native encode/interpret to constant > fold (nearly) all BIT_FIELD_REFs. */ > if (CONSTANT_CLASS_P (arg0) > && can_native_interpret_type_p (type) > && BITS_PER_UNIT == 8 > && tree_fits_uhwi_p (op1) > && tree_fits_uhwi_p (op2)) > > so this patch adds the checks to the first pattern too. This is needed > for POLY_INT_CST bit positions. > > Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu. > Also tested by comparing the before and after assembly output for at > least one target per CPU directory. OK to install? > > Richard > > > 2018-01-04 Richard Sandiford <richard.sandiford@linaro.org> > > gcc/ > * fold-const.c (fold_ternary_loc): Check tree_fits_uhwi_p before > using tree_to_uhwi. OK. jeff
On Thu, Jan 4, 2018 at 11:06 AM, Richard Sandiford <richard.sandiford@linaro.org> wrote: > The first BIT_FIELD_REF folding pattern assumed without checking that > operands satisfy tree_fits_uhwi_p. The second pattern does check this: > > /* On constants we can use native encode/interpret to constant > fold (nearly) all BIT_FIELD_REFs. */ > if (CONSTANT_CLASS_P (arg0) > && can_native_interpret_type_p (type) > && BITS_PER_UNIT == 8 > && tree_fits_uhwi_p (op1) > && tree_fits_uhwi_p (op2)) > > so this patch adds the checks to the first pattern too. This is needed > for POLY_INT_CST bit positions. > > Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu. > Also tested by comparing the before and after assembly output for at > least one target per CPU directory. OK to install? Ok. It's of course because verify_expr verified that. Richard. > Richard > > > 2018-01-04 Richard Sandiford <richard.sandiford@linaro.org> > > gcc/ > * fold-const.c (fold_ternary_loc): Check tree_fits_uhwi_p before > using tree_to_uhwi. > > Index: gcc/fold-const.c > =================================================================== > --- gcc/fold-const.c 2018-01-03 21:42:34.349039784 +0000 > +++ gcc/fold-const.c 2018-01-04 10:06:02.165809202 +0000 > @@ -11643,7 +11643,9 @@ fold_ternary_loc (location_t loc, enum t > if (TREE_CODE (arg0) == VECTOR_CST > && (type == TREE_TYPE (TREE_TYPE (arg0)) > || (TREE_CODE (type) == VECTOR_TYPE > - && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0))))) > + && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0)))) > + && tree_fits_uhwi_p (op1) > + && tree_fits_uhwi_p (op2)) > { > tree eltype = TREE_TYPE (TREE_TYPE (arg0)); > unsigned HOST_WIDE_INT width = tree_to_uhwi (TYPE_SIZE (eltype));
Index: gcc/fold-const.c =================================================================== --- gcc/fold-const.c 2018-01-03 21:42:34.349039784 +0000 +++ gcc/fold-const.c 2018-01-04 10:06:02.165809202 +0000 @@ -11643,7 +11643,9 @@ fold_ternary_loc (location_t loc, enum t if (TREE_CODE (arg0) == VECTOR_CST && (type == TREE_TYPE (TREE_TYPE (arg0)) || (TREE_CODE (type) == VECTOR_TYPE - && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0))))) + && TREE_TYPE (type) == TREE_TYPE (TREE_TYPE (arg0)))) + && tree_fits_uhwi_p (op1) + && tree_fits_uhwi_p (op2)) { tree eltype = TREE_TYPE (TREE_TYPE (arg0)); unsigned HOST_WIDE_INT width = tree_to_uhwi (TYPE_SIZE (eltype));
The first BIT_FIELD_REF folding pattern assumed without checking that operands satisfy tree_fits_uhwi_p. The second pattern does check this: /* On constants we can use native encode/interpret to constant fold (nearly) all BIT_FIELD_REFs. */ if (CONSTANT_CLASS_P (arg0) && can_native_interpret_type_p (type) && BITS_PER_UNIT == 8 && tree_fits_uhwi_p (op1) && tree_fits_uhwi_p (op2)) so this patch adds the checks to the first pattern too. This is needed for POLY_INT_CST bit positions. Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linux-gnu. Also tested by comparing the before and after assembly output for at least one target per CPU directory. OK to install? Richard 2018-01-04 Richard Sandiford <richard.sandiford@linaro.org> gcc/ * fold-const.c (fold_ternary_loc): Check tree_fits_uhwi_p before using tree_to_uhwi.