[Bug target/58314] SH4 error: 'asm' operand requires impossible reload

[olegendo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58314

--- Comment #11 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to Oleg Endo from comment #10)
> 
> This usually happens because SH2A insns are output -- 32 bit displacement
> addressing insns which are more flexible -- even though the target is
> non-SH2A.  This is what the comment above the reg_reg pattern is talking
> about.
> 
> (There is no compiler error because the target type is not passed down to
> the assembler by the compiler).

This patch can be applied to enable the error message by the assembler:

Index: gcc/config/sh/sh.h
===================================================================
--- gcc/config/sh/sh.h    (revision 205190)
+++ gcc/config/sh/sh.h    (working copy)
@@ -267,9 +267,25 @@
 #define SUBTARGET_ASM_RELAX_SPEC "%{m4*:-isa=sh4-up}"
 #endif

+/* Define which ISA type to pass to the assembler.
+   For SH4 we pass SH4A to allow using some instructions that are available
+   on some SH4 variants, but officially are part of the SH4A ISA.  */
 #define SH_ASM_SPEC \
  "%(subtarget_asm_endian_spec) %{mrelax:-relax %(subtarget_asm_relax_spec)} \
 %(subtarget_asm_isa_spec) %(subtarget_asm_spec) \
+%{m1:--isa=sh} \
+%{m2:--isa=sh2} \
+%{m2e:--isa=sh2e} \
+%{m3:--isa=sh3} \
+%{m3e:--isa=sh3e} \
+%{m4:--isa=sh4a} \
+%{m4-single:--isa=sh4a} \
+%{m4-single-only:--isa=sh4a} \
+%{m4-nofpu:--isa=sh4a-nofpu} \
+%{m4a:--isa=sh4a} \
+%{m4a-single:--isa=sh4a} \
+%{m4a-single-only:--isa=sh4a} \
+%{m4a-nofpu:--isa=sh4a-nofpu} \
 %{m2a:--isa=sh2a} \
 %{m2a-single:--isa=sh2a} \
 %{m2a-single-only:--isa=sh2a} \