[PATCH] cselib: Skip BImode while keeping track of subvalue relations [PR107088]

Stefan Schulze Frielinghaus stefansf@linux.ibm.com
Tue Oct 4 11:28:50 GMT 2022

For BImode get_narrowest_mode evaluates to QImode but BImode < QImode.
Thus FOR_EACH_MODE_UNTIL never reaches BImode and iterates until OImode
for which no wider mode exists so we end up with VOIDmode and fail.
Fixed by adding a size guard so we effectively skip BImode.

Bootstrap and regtest are currently running on x64.  Assuming they pass
ok for mainline?


	PR rtl-optimization/107088
	* cselib.cc (new_cselib_val): Skip BImode while keeping track of
	subvalue relations.
 gcc/cselib.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/cselib.cc b/gcc/cselib.cc
index 9b582e5d3d6..2abc763a3f8 100644
--- a/gcc/cselib.cc
+++ b/gcc/cselib.cc
@@ -1571,6 +1571,7 @@ new_cselib_val (unsigned int hash, machine_mode mode, rtx x)
   scalar_int_mode int_mode;
   if (REG_P (x) && is_int_mode (mode, &int_mode)
+      && GET_MODE_SIZE (int_mode) > 1
       && REG_VALUES (REGNO (x)) != NULL
       && (!cselib_current_insn || !DEBUG_INSN_P (cselib_current_insn)))

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