[golang-dev] C_PBIT in 5a, 5l, 5c, 5g

	Ziutek
	Nov 7, 2012 at 11:09 pm

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Ziutek: After this fix my test code: TEXT ·PrePost (SB), 7, $0 MOVW 8(R0), R1 MOVW.IB 8(R0), R1 MOVW.IBW 8(R0), R1 MOVW.IA 8(R0), R1 MOVW.IAW 8(R0), R1 MOVD 8(R0), F0 MOVD.IBW 8(R0), F0 MOVD.IA 8(R0), F0 RET disassembles to: Dump of assembler code for function github.com/ziutek/matrix.PrePost: => 0x0002f178 <+0>: 08 10 90 e5 ldr r1, [r0, #8] 0x0002f17c <+4>: 08 10 90 e5 ldr r1, [r0, #8] 0x0002f180 <+8>: 08 10 b0 e5 ldr r1, [r0, #8]! 0x0002f184 <+12>: 08 10 90 e4 ldr r1, [r0], #8 0x0002f188 <+16>: 08 10

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Dave Cheney: Hi, I've been trying to follow this thread as I am concerned with any 5x codegen bugs, but it is still not clear to me what the problem is your are fixing. I believe you are saying the 5a syntax differs from the description in the arm literature, if that is the case I am not surprised, but as of now it is the dialect we have. Do the affected instruction suffixes appear anywhere in the .s files in the stdlib? If not then I guess it is ok to fix their interpretation, but if they are in use then
Ziutek: There is definitely a bug in MOVW.IA (increment after) and MOVW.IBW (increment before) handling. Generated code has negated offset and wrong P bit. I can't run all.bash for now because I tried this fix on slow qemu emulator. No I can test on real Cortex-A9 machine and compilation fails: pkg/go/build cmd/go ./make.bash: line 119: 12656 Segmentation fault "$GOTOOLDIR"/ go_bootstrap clean -i std I check for ARM assembler code in tree. There is no instructions with .IB suffix but there are
Dave Cheney: What does objdump -dS say ?

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