[PATCH] cplxlower: Avoid a transform when looking at a default definition
Martin Jambor
mjambor@suse.cz
Fri Oct 16 18:46:39 GMT 2020
Hi,
in PR 97456, IPA-SRA triggers a bug in tree-complex.c where it
converts:
<bb 2>
a$_M_value_21 = COMPLEX_EXPR <ISRA.18_10(D), ISRA.18_10(D)>;
(where ISRA.18 is IPA-SRA created PARM_DECL with DECL_IGNORED_P set,
which is why it only happens with IPA-SRA) into:
<bb 2>
a$_M_value_21 = COMPLEX_EXPR <a$_M_value$real_10(D), a$_M_value$real_10(D)>;
i.e. it replaces two uses of the parameter default-def with two
uninitialized default-defs of a new variable - all in hope to produce
code with better debug info.
This patch fixes it by avoiding the transform when the SSA_NAME to be
replaced is a default definition. Bootstrapped and tested on
x86_64-linux. OK for trunk and the gcc-10 branch?
Thanks,
Martin
gcc/ChangeLog:
2020-10-16 Martin Jambor <mjambor@suse.cz>
PR tree-optimization/97456
* tree-complex.c (set_component_ssa_name): Do not replace ignored decl
default definitions with new component vars. Reorder if conditions.
gcc/testsuite/ChangeLog:
2020-10-16 Martin Jambor <mjambor@suse.cz>
PR tree-optimization/97456
* gcc.dg/tree-ssa/pr97456.c: New test.
---
gcc/testsuite/gcc.dg/tree-ssa/pr97456.c | 40 +++++++++++++++++++++++++
gcc/tree-complex.c | 6 ++--
2 files changed, 44 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr97456.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr97456.c b/gcc/testsuite/gcc.dg/tree-ssa/pr97456.c
new file mode 100644
index 00000000000..5171c9b4577
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr97456.c
@@ -0,0 +1,40 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fwhole-program" } */
+
+
+float val2 = 1.710780f;
+float val3;
+volatile float vf;
+
+int __attribute__((noipa))
+get_bool (void)
+{
+ return 1;
+}
+
+int __attribute__((noinline))
+wrong (float *pos)
+{
+ _Complex float a;
+
+ __real__ a = *pos;
+ __imag__ a = *pos;
+
+ _Complex float b = 0 + 0i;
+
+ b = b + a;
+
+ if (b == 0.0f)
+ return 1;
+
+ vf = __imag__ b;
+ return 0;
+}
+
+int main(int argc, char **argv) {
+ float val = get_bool () == 1 ? val2 : val3;
+
+ if ((wrong(&val), wrong(&val)))
+ __builtin_abort ();
+ return 0;
+}
diff --git a/gcc/tree-complex.c b/gcc/tree-complex.c
index 2e54bbb917c..71ad7c18523 100644
--- a/gcc/tree-complex.c
+++ b/gcc/tree-complex.c
@@ -570,8 +570,10 @@ set_component_ssa_name (tree ssa_name, bool imag_p, tree value)
/* Replace an anonymous base value with the variable from cvc_lookup.
This should result in better debug info. */
if (SSA_NAME_VAR (ssa_name)
- && (!SSA_NAME_VAR (value) || DECL_IGNORED_P (SSA_NAME_VAR (value)))
- && !DECL_IGNORED_P (SSA_NAME_VAR (ssa_name)))
+ && !DECL_IGNORED_P (SSA_NAME_VAR (ssa_name))
+ && (!SSA_NAME_VAR (value)
+ || (DECL_IGNORED_P (SSA_NAME_VAR (value))
+ && !SSA_NAME_IS_DEFAULT_DEF (value))))
{
comp = get_component_var (SSA_NAME_VAR (ssa_name), imag_p);
replace_ssa_name_symbol (value, comp);
--
2.28.0
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