PR rtl-optimization/90275 * cse.c (cse_insn): Delete no-op register moves too. PR rtl-optimization/90275 * gcc.c-torture/compile/pr90275.c: New test. diff --git a/gcc/cse.c b/gcc/cse.c index 79ee0ce80e3..1779bb9a333 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -4625,7 +4625,7 @@ cse_insn (rtx_insn *insn) for (i = 0; i < n_sets; i++) { bool repeat = false; - bool mem_noop_insn = false; + bool noop_insn = false; rtx src, dest; rtx src_folded; struct table_elt *elt = 0, *p; @@ -5324,9 +5324,11 @@ cse_insn (rtx_insn *insn) } /* Similarly, lots of targets don't allow no-op - (set (mem x) (mem x)) moves. */ + (set (mem x) (mem x)) moves. Even (set (reg x) (reg x)) + might be impossible for certain registers (like CC registers). */ else if (n_sets == 1 - && MEM_P (trial) + && ! CALL_P (insn) + && (MEM_P (trial) || REG_P (trial)) && MEM_P (dest) && rtx_equal_p (trial, dest) && !side_effects_p (dest) @@ -5334,7 +5336,7 @@ cse_insn (rtx_insn *insn) || insn_nothrow_p (insn))) { SET_SRC (sets[i].rtl) = trial; - mem_noop_insn = true; + noop_insn = true; break; } @@ -5562,8 +5564,8 @@ cse_insn (rtx_insn *insn) sets[i].rtl = 0; } - /* Similarly for no-op MEM moves. */ - else if (mem_noop_insn) + /* Similarly for no-op moves. */ + else if (noop_insn) { if (cfun->can_throw_non_call_exceptions && can_throw_internal (insn)) cse_cfg_altered = true; diff --git a/gcc/testsuite/gcc.c-torture/compile/pr90275.c b/gcc/testsuite/gcc.c-torture/compile/pr90275.c new file mode 100644 index 00000000000..83e0df77226 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr90275.c @@ -0,0 +1,27 @@ +a, b, c; + +long long d; + +e() { + + char f; + + for (;;) { + + c = a = c ? 5 : 0; + + if (f) { + + b = a; + + f = d; + + } + + (d || b) < (a > e) ?: (b ? 0 : f) || (d -= f); + + } + +} + +