| Message ID | 000c01d0e532$823066c0$86913440$@arm.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Sep 2, 2015 at 5:50 AM, Bin Cheng <bin.cheng@arm.com> wrote: > Hi, > When calling get_shiftadd_cost, the mult_op is stripped at caller places. > We should look into unnecessary conversion in op1 before checking equality, > otherwise it computes wrong shiftadd cost. This patch picks this small > issue up. > > Bootstrap and test on x86_64 and aarch64 along with other patches. Is it > OK? Just do STRIP_NOPS (op1) unconditionally? Thus STRIP_NOPS (op1); mult_in_op1 = operand_equal_p (op1, mult, 0); ok with that change. Thanks, Richard. > Thanks, > bin > > 2015-08-31 Bin Cheng <bin.cheng@arm.com> > > * tree-ssa-loop-ivopts.c (get_shiftadd_cost): Look into > unnecessary type conversion for OP1.
On Wed, Sep 2, 2015 at 8:32 PM, Richard Biener <richard.guenther@gmail.com> wrote: > On Wed, Sep 2, 2015 at 5:50 AM, Bin Cheng <bin.cheng@arm.com> wrote: >> Hi, >> When calling get_shiftadd_cost, the mult_op is stripped at caller places. >> We should look into unnecessary conversion in op1 before checking equality, >> otherwise it computes wrong shiftadd cost. This patch picks this small >> issue up. >> >> Bootstrap and test on x86_64 and aarch64 along with other patches. Is it >> OK? > > Just do STRIP_NOPS (op1) unconditionally? Thus > > STRIP_NOPS (op1); > mult_in_op1 = operand_equal_p (op1, mult, 0); > > ok with that change. Patch committed as suggested. Thanks, bin
Index: gcc/tree-ssa-loop-ivopts.c =================================================================== --- gcc/tree-ssa-loop-ivopts.c (revision 227163) +++ gcc/tree-ssa-loop-ivopts.c (working copy) @@ -3884,12 +4038,14 @@ get_shiftadd_cost (tree expr, machine_mode mode, c int m = exact_log2 (int_cst_value (cst)); int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode)); int as_cost, sa_cost; - bool mult_in_op1; + bool mult_in_op1 = false; if (!(m >= 0 && m < maxm)) return false; - mult_in_op1 = operand_equal_p (op1, mult, 0); + if (operand_equal_p (op1, mult, 0) + || operand_equal_p (STRIP_NOPS (op1), mult, 0)) + mult_in_op1 = true; as_cost = add_cost (speed, mode) + shift_cost (speed, mode, m);