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Balazs Kezes 49d3118621 Incorrect function call code on ARMv6
On 2016-08-11 09:24 +0100, Balazs Kezes wrote:
> I think it's just that that copy_params() never restores the spilled
> registers. Maybe it needs some extra code at the end to see if any
> parameters have been spilled to stack and then restore them?

I've spent some time on this and I've found an alternative solution.
Although I'm not entirely sure about it but I've attached a patch
nevertheless.

And while poking at that I've found another problem affecting the
unsigned long long division on arm and I've attached a patch for that
too.

More details in the patches themselves. Please review and consider them
for merging! Thank you!

--
Balazs

[PATCH 1/2] Fix slow unsigned long long division on ARM

The macro AEABI_UXDIVMOD expands to this bit:

  #define AEABI_UXDIVMOD(name,type, rettype, typemacro)                     \
  ...
      while (num >= den) {                                                  \
  ...
          while ((q << 1) * den <= num && q * den <= typemacro ## _MAX / 2) \
              q <<= 1;                                                      \
  ...

With the current ULONG_MAX version the inner loop goes only until 4
billion so the outer loop will progress very slowly if num is large.
With ULLONG_MAX the inner loop works as expected. The current version is
probably a result of a typo.

The following bash snippet demonstrates the bug:

  $ uname -a
  Linux eper 4.4.16-2-ARCH #1 Wed Aug 10 20:03:13 MDT 2016 armv6l GNU/Linux
  $ cat div.c
  int printf(const char *, ...);
  int main(void) {
    unsigned long long num, denom;
    num = 12345678901234567ULL;
    denom = 7;
    printf("%lld\n", num / denom);
    return 0;
  }
  $ time tcc -run div.c
  1763668414462081

  real    0m16.291s
  user    0m15.860s
  sys     0m0.020s

[PATCH 2/2] Fix long long dereference during argument passing on ARMv6

For some reason the code spills the register to the stack. copy_params
in arm-gen.c doesn't expect this so bad code is generated. It's not
entirely clear why the saving part is necessary. It was added in commit
59c35638 with the comment "fixed long long code gen bug" with no further
clarification. Given that tcctest.c passes without this, maybe it's no
longer needed? Let's remove it.

Also add a new testcase just for this. After I've managed to make the
tests compile on a raspberry pi, I get the following diff without this
patch:

  --- test.ref    2016-08-22 22:12:43.380000000 +0100
  +++ test.out3   2016-08-22 22:12:49.990000000 +0100
  @@ -499,7 +499,7 @@
   2
   1 0 1 0
   4886718345
  -shift: 9 9 9312
  +shift: 291 291 291
   shiftc: 36 36 2328
   shiftc: 0 0 9998683865088
   manyarg_test:

More discussion on this thread:
https://lists.nongnu.org/archive/html/tinycc-devel/2016-08/msg00004.html
2016-10-01 23:10:11 +02:00
examples Revert "Make ex1.c and ex4.c be executable on any systems" 2012-06-12 15:45:13 +02:00
include Avoid conflicting definition for va_list on 64-bit Macs 2016-08-04 13:14:52 -04:00
lib Incorrect function call code on ARMv6 2016-10-01 23:10:11 +02:00
tests Incorrect function call code on ARMv6 2016-10-01 23:10:11 +02:00
win32 build: revert Makefiles to 0.9.26 state (mostly) 2016-10-01 21:06:33 +02:00
.gitignore Move utility functions trimfront/back to tccpp.c 2016-04-13 14:33:21 +03:00
arm64-gen.c Replace pointer casts with calls to (read|write)(16|32|64)le. 2015-11-19 18:21:14 +00:00
arm-gen.c Merge the integer members of union CValue into "uint64_t i". 2015-11-17 19:09:35 +00:00
c67-gen.c Merge the integer members of union CValue into "uint64_t i". 2015-11-17 19:09:35 +00:00
Changelog Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
CodingStyle CodingStyle: Remove reference to misaligned struct CString. 2016-01-06 19:09:28 +00:00
coff.h Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
configure build: restore out-of-tree support 2016-10-01 21:06:53 +02:00
conftest.c Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
COPYING changed license to LGPL 2003-05-24 14:18:56 +00:00
elf.h tccgen: scopes levels for local symbols (update 1) 2016-05-05 20:04:00 +02:00
i386-asm.c x86-asm: Reject some invalid arith imm8 instruction 2016-05-16 05:10:21 +02:00
i386-asm.h x86-asm: Reject some invalid arith imm8 instruction 2016-05-16 05:10:21 +02:00
i386-gen.c gtst_addr(): short conditional jumps (i386, x86_64) 2016-09-30 07:33:20 -07:00
i386-tok.h x86-64-asm: Add mov[sz]xq opcodes 2016-05-12 00:57:02 +02:00
il-gen.c Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
il-opcodes.h Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
libtcc.c Revert "-fnormalize-inc-dirs" 2016-10-01 21:57:22 +02:00
libtcc.h libtcc: filetype cleanup 2016-10-01 20:46:16 +02:00
Makefile Fix building man pages. 2016-10-01 13:25:46 -07:00
README Fix building instruction wrt make/gmake 2013-04-08 23:26:27 +02:00
RELICENSING Adding two more people to the RELICENSING file. 2015-07-31 16:56:23 -04:00
stab.def Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
stab.h Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
tcc-doc.texi Revert "-fnormalize-inc-dirs" 2016-10-01 21:57:22 +02:00
tcc.c tcc -E: add one space in cases: tiny solution 2016-10-01 21:52:11 +02:00
tcc.h Revert "-fnormalize-inc-dirs" 2016-10-01 21:57:22 +02:00
tccasm.c tccpp: cleanup 2016-10-01 20:26:50 +02:00
tcccoff.c Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
tccelf.c tccelf: allow multiple declaration of bss/common symbols 2016-10-01 22:01:33 +02:00
tccgen.c Incorrect function call code on ARMv6 2016-10-01 23:10:11 +02:00
tcclib.h Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
tccpe.c libtcc: reimplement option -Wl,[-no]-whöle-archive 2016-10-01 20:54:45 +02:00
tccpp.c tccpp: parse_line_comment: fix possible buffer overrun 2016-10-01 22:01:25 +02:00
tccrun.c Revert part of "fix installation amd bcheck for Windows" 2016-10-01 20:47:36 +02:00
tcctok.h Revert part of "fix installation amd bcheck for Windows" 2016-10-01 20:47:36 +02:00
texi2pod.pl Revert all of my changes to directories & codingstyle. 2015-07-29 16:57:12 -04:00
TODO Insert spaces between certain tokens when tcc is invoked with -E. 2016-05-09 19:27:31 +01:00
VERSION Release TinyCC 0.9.26 2013-02-15 14:23:58 +01:00
x86_64-asm.h x86-asm: Reject some invalid arith imm8 instruction 2016-05-16 05:10:21 +02:00
x86_64-gen.c gtst_addr(): short conditional jumps (i386, x86_64) 2016-09-30 07:33:20 -07:00

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Fabrice Bellard.