On 06/12/2020 09:33 PM, Nick Desaulniers wrote:
IIUC the bug report correctly, it looks like LLVM is failing for the __put_user_asm2_goto case for -m32. A simple reproducer: https://godbolt.org/z/jBBF9b void foo(long long in, long long* out) { asm volatile( "stw%X1 %0, %1\n\t" "stw%X1 %L0, %L1" ::"r"(in), "m"(*out)); } prints (in GCC): foo: stw 3, 0(5) stw 4, 4(5) blr (first time looking at ppc assembler, seems constants and registers are not as easy to distinguish, https://developer.ibm.com/technologies/linux/articles/l-ppc/ say "Get used to it." LOL, ok).
When I do ppc-linux-objdump -d vmlinux, registers and constants are easily distinguished, see below.
c0002284 <start_here>: c0002284: 3c 40 c0 3c lis r2,-16324 c0002288: 60 42 45 00 ori r2,r2,17664 c000228c: 3c 82 40 00 addis r4,r2,16384 c0002290: 38 84 04 30 addi r4,r4,1072 c0002294: 7c 93 43 a6 mtsprg 3,r4 c0002298: 3c 20 c0 3e lis r1,-16322 c000229c: 38 21 e0 00 addi r1,r1,-8192 c00022a0: 38 00 00 00 li r0,0 c00022a4: 94 01 1f f0 stwu r0,8176(r1) c00022a8: 48 35 e7 41 bl c03609e8 <early_init> c00022ac: 38 60 00 00 li r3,0 c00022b0: 7f e4 fb 78 mr r4,r31 c00022b4: 48 35 e7 8d bl c0360a40 <machine_init> c00022b8: 48 35 eb e1 bl c0360e98 <MMU_init> c00022bc: 3c c0 c0 3c lis r6,-16324 c00022c0: 3c c6 40 00 addis r6,r6,16384 c00022c4: 7c df c3 a6 mtspr 799,r6 c00022c8: 3c 80 c0 00 lis r4,-16384 c00022cc: 60 84 22 e4 ori r4,r4,8932 c00022d0: 3c 84 40 00 addis r4,r4,16384 c00022d4: 38 60 10 02 li r3,4098 c00022d8: 7c 9a 03 a6 mtsrr0 r4 c00022dc: 7c 7b 03 a6 mtsrr1 r3 c00022e0: 4c 00 00 64 rfi c00022e4: 7c 00 02 e4 tlbia c00022e8: 7c 00 04 ac hwsync c00022ec: 3c c6 c0 00 addis r6,r6,-16384 c00022f0: 3c a0 c0 3c lis r5,-16324 c00022f4: 60 a5 40 00 ori r5,r5,16384 c00022f8: 90 a0 00 f0 stw r5,240(0) c00022fc: 3c a5 40 00 addis r5,r5,16384 c0002300: 90 c5 00 00 stw r6,0(r5) c0002304: 38 80 10 32 li r4,4146 c0002308: 3c 60 c0 35 lis r3,-16331 c000230c: 60 63 d6 a8 ori r3,r3,54952 c0002310: 7c 7a 03 a6 mtsrr0 r3 c0002314: 7c 9b 03 a6 mtsrr1 r4 c0002318: 4c 00 00 64 rfi For GCC, I think you call tell you want register names with -mregnames Christophe
