From: "J. Neuschäfer" <j...@posteo.net> PowerPC general-purpose registers are historically specified as plain numbers (0-31), which makes them hard to distinguish from immediates. For this reason, include/ppc_asm.tmpl defines aliases named r0-r31. This can still lead to uncaught mistakes if a register is used in place of a number.
Instead of (e.g.) 5 use %r5, which will result in an assembler warning if used as a number. Turn these warnings into errors by passing `--fatal-warnings` to the assembler. I verified with gazerbeam_defconfig (MPC83xx) and qemu-ppce500_defconfig (MPC85xx) that this patch results in the same machine code. Signed-off-by: J. Neuschäfer <j...@posteo.net> --- arch/powerpc/config.mk | 2 +- include/ppc_asm.tmpl | 66 +++++++++++++++++++++++++------------------------- 2 files changed, 34 insertions(+), 34 deletions(-) diff --git a/arch/powerpc/config.mk b/arch/powerpc/config.mk index dd0124cace19be060d9374c440b0f35e5dbd801a..6e30df6504ecc62eff3dc3cb7d0a3e9cc9dcf4b3 100644 --- a/arch/powerpc/config.mk +++ b/arch/powerpc/config.mk @@ -8,7 +8,7 @@ LDFLAGS_FINAL += --bss-plt PLATFORM_RELFLAGS += -fpic -mrelocatable -ffunction-sections \ -fdata-sections -mcall-linux -PF_CPPFLAGS_POWERPC := $(call cc-option,-fno-ira-hoist-pressure,) +PF_CPPFLAGS_POWERPC := $(call cc-option,-fno-ira-hoist-pressure,) $(call cc-option,-Xassembler --fatal-warnings,) PLATFORM_CPPFLAGS += -D__powerpc__ -ffixed-r2 -m32 $(PF_CPPFLAGS_POWERPC) KBUILD_LDFLAGS += -m32 -melf32ppclinux diff --git a/include/ppc_asm.tmpl b/include/ppc_asm.tmpl index db7b1668d99a60ecd3992f0e090b37a7f0c23e00..0b858c41e32398d074069f9f0fdbc8e28d8e407e 100644 --- a/include/ppc_asm.tmpl +++ b/include/ppc_asm.tmpl @@ -45,40 +45,40 @@ /*************************************************************************** - * Register names + * Register names. The %r1 offers some error-checking in GNU as. */ -#define r0 0 -#define r1 1 -#define r2 2 -#define r3 3 -#define r4 4 -#define r5 5 -#define r6 6 -#define r7 7 -#define r8 8 -#define r9 9 -#define r10 10 -#define r11 11 -#define r12 12 -#define r13 13 -#define r14 14 -#define r15 15 -#define r16 16 -#define r17 17 -#define r18 18 -#define r19 19 -#define r20 20 -#define r21 21 -#define r22 22 -#define r23 23 -#define r24 24 -#define r25 25 -#define r26 26 -#define r27 27 -#define r28 28 -#define r29 29 -#define r30 30 -#define r31 31 +#define r0 %r0 +#define r1 %r1 +#define r2 %r2 +#define r3 %r3 +#define r4 %r4 +#define r5 %r5 +#define r6 %r6 +#define r7 %r7 +#define r8 %r8 +#define r9 %r9 +#define r10 %r10 +#define r11 %r11 +#define r12 %r12 +#define r13 %r13 +#define r14 %r14 +#define r15 %r15 +#define r16 %r16 +#define r17 %r17 +#define r18 %r18 +#define r19 %r19 +#define r20 %r20 +#define r21 %r21 +#define r22 %r22 +#define r23 %r23 +#define r24 %r24 +#define r25 %r25 +#define r26 %r26 +#define r27 %r27 +#define r28 %r28 +#define r29 %r29 +#define r30 %r30 +#define r31 %r31 #if defined(CONFIG_MPC8xx) -- 2.45.2
