https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97715
--- Comment #18 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/function.c.jj 2020-10-31 17:41:19.756740009 +0100
+++ gcc/function.c 2020-11-04 17:56:53.790403571 +0100
@@ -5871,6 +5871,8 @@ gen_call_used_regs_seq (rtx_insn *ret, u
continue;
if (fixed_regs[regno])
continue;
+ if (!TEST_HARD_REG_BIT (accessible_reg_set, regno))
+ continue;
if (REGNO_REG_SET_P (live_out, regno))
continue;
if (only_gpr
--- gcc/testsuite/gcc.target/i386/zero-scratch-regs-32.c.jj 2020-11-04
17:59:19.063795531 +0100
+++ gcc/testsuite/gcc.target/i386/zero-scratch-regs-32.c 2020-11-04
17:59:01.956984879 +0100
@@ -0,0 +1,5 @@
+/* PR target/97715 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=all -mno-80387" } */
+
+#include "../../c-c++-common/zero-scratch-regs-10.c"
isn't enough though, because while the st to st(7) registers are inaccessible
with -mno-80387, the MMX registers are accessible, so I think the
zero_all_st_registers change is needed too.
