From e0e388998b797da09a8c018f6f94d1358fd4b8f1 Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Thu, 7 Jul 2022 22:06:19 +0000 Subject: Fix tree-opt/PR106087: ICE with inline-asm with multiple output and assigned only static vars The problem here is that when we mark the ssa name that was referenced in the now removed dead store (to a write only static variable), the inline-asm would also be removed even though it was defining another ssa name. This fixes the problem by checking to make sure that the statement was only defining one ssa name. Committed as approved after a bootstrapped and tested on x86_64 with no regressions. PR tree-optimization/106087 gcc/ChangeLog: * tree-ssa-dce.cc (simple_dce_from_worklist): Check to make sure the statement is only defining one operand. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/inline-asm-1.c: New test. (cherry picked from commit 71e3daa31cfa35ee58e5899cb00767be92227fd2) --- gcc/testsuite/gcc.c-torture/compile/inline-asm-1.c | 14 ++++++++++++++ gcc/tree-ssa-dce.cc | 7 +++++++ 2 files changed, 21 insertions(+) create mode 100644 gcc/testsuite/gcc.c-torture/compile/inline-asm-1.c diff --git a/gcc/testsuite/gcc.c-torture/compile/inline-asm-1.c b/gcc/testsuite/gcc.c-torture/compile/inline-asm-1.c new file mode 100644 index 00000000000..0044cb761b6 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/inline-asm-1.c @@ -0,0 +1,14 @@ +/* PR tree-opt/106087, + simple_dce_from_worklist would delete the + inline-asm when it was still being referenced + by the other ssa name. */ + +static int t; + +int f(void) +{ + int tt, tt1; + asm("":"=r"(tt), "=r"(tt1)); + t = tt1; + return tt; +} diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc index 2067b711d5b..4b7b664867d 100644 --- a/gcc/tree-ssa-dce.cc +++ b/gcc/tree-ssa-dce.cc @@ -2060,6 +2060,13 @@ simple_dce_from_worklist (bitmap worklist) if (gimple_has_side_effects (t)) continue; + /* The defining statement needs to be defining only this name. + ASM is the only statement that can define more than one + (non-virtual) name. */ + if (is_a(t) + && !single_ssa_def_operand (t, SSA_OP_DEF)) + continue; + /* Don't remove statements that are needed for non-call eh to work. */ if (stmt_unremovable_because_of_non_call_eh_p (cfun, t)) -- cgit v1.2.3