| Message ID | a07dda88-000a-fef5-c2b7-5d155540b013@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Richard, Thanks for the review. On 23/09/16 17:19, Richard Biener wrote: > On Fri, Sep 23, 2016 at 12:24 AM, kugan > <kugan.vivekanandarajah@linaro.org> wrote: >> Hi, >> As Richard pointed out in PR77677, TREE_OVERFLOW is not cleared in IPA-VRP. >> There are three places in which we set value_range: >> >> >> 1. When value ranges are obtained from SSA_NAME with get_range_info with >> wide_int_to_tree. In this case we will not have TREE_OVERFLOW set. >> >> 2. When we vrp_meet/vrp_intersect_ranges two ranges. It does int_const_binop >> but AFAIK this does not set TREE_OVERFLOW. >> >> 3. When we create range from constant. This is the problem bit and we need >> to clear TREE_OVERFLOW here. >> >> Attached patch clears the TREE_OVERFLOW in 3rd case. Bootstrap and >> regression testing are ongoing. Is this OK if there is no regression. > > Ok. Though it would be nice to drop it at the source (that is, the point we > initialize the IPA-CP lattice and its modifications). In ipa_compute_jump_function_for_egde, value_range lattice is not set for constants as this information is already there in IPA_JF_CONSTANT. That is, we initialize only when we get it from get_range_info (SSA_NAMES); others are set to unknown. Though we can set it at this point, it can be inefficient in terms of streaming in/out this data. While propagating we get it from IPA_JF_CONSTANT. Thanks, Kugan > Richard. > >> Thanks, >> Kugan >> >> >> gcc/ChangeLog: >> >> 2016-09-23 Kugan Vivekanandarajah <kuganv@linaro.org> >> >> PR ipa/77677 >> * ipa-cp.c (propagate_vr_accross_jump_function):Drop TREE_OVERFLOW >> from constant while creating value range. >> >> gcc/testsuite/ChangeLog: >> >> 2016-09-23 Kugan Vivekanandarajah <kuganv@linaro.org> >> >> PR ipa/77677 >> * gcc.dg/torture/pr77677.c: New test.
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c index cb60f1e..f735ef7 100644 --- a/gcc/ipa-cp.c +++ b/gcc/ipa-cp.c @@ -2065,6 +2065,8 @@ propagate_vr_accross_jump_function (cgraph_edge *cs, tree val = ipa_get_jf_constant (jfunc); if (TREE_CODE (val) == INTEGER_CST) { + if (TREE_OVERFLOW_P (val)) + val = drop_tree_overflow (val); jfunc->vr_known = true; jfunc->m_vr.type = VR_RANGE; jfunc->m_vr.min = val; diff --git a/gcc/testsuite/gcc.dg/torture/pr77677.c b/gcc/testsuite/gcc.dg/torture/pr77677.c index e69de29..af3f0b0 100644 --- a/gcc/testsuite/gcc.dg/torture/pr77677.c +++ b/gcc/testsuite/gcc.dg/torture/pr77677.c @@ -0,0 +1,18 @@ +/* PR ipa/77677 */ +/* { dg-do compile } */ + +int a, b; + +static void fn1 (short p1) +{ + a = -p1; + if (a || b) + __builtin_printf ("%d\n", b); +} + +int main () +{ + int c[] = { 40000 }; + fn1 (c[0]); + return 0; +}