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| author | David Hendricks <dhendrix@chromium.org> | 2013-03-06 20:43:55 -0800 |
|---|---|---|
| committer | Ronald G. Minnich <rminnich@gmail.com> | 2013-03-08 23:14:26 +0100 |
| commit | ae0e8d3613ad9cb6872c58cd95fc9774b3b17f5b (patch) | |
| tree | 452b6c60e2f9bf9f5d0c373a27eed092675e13e6 /src/arch/x86 | |
| parent | 31c5e07a04e90c03822d216d2dc92454b42e21ce (diff) | |
| download | coreboot-ae0e8d3613ad9cb6872c58cd95fc9774b3b17f5b.tar.xz | |
Eliminate do_div().
This eliminates the use of do_div() in favor of using libgcc
functions.
This was tested by building and booting on Google Snow (ARMv7)
and Qemu (x86). printk()s which use division in vtxprintf() look good.
Change-Id: Icad001d84a3c05bfbf77098f3d644816280b4a4d
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/2606
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Diffstat (limited to 'src/arch/x86')
| -rw-r--r-- | src/arch/x86/Makefile.inc | 8 | ||||
| -rw-r--r-- | src/arch/x86/include/div64.h | 30 |
2 files changed, 4 insertions, 34 deletions
diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc index 98723f3f1a..0892efd37b 100644 --- a/src/arch/x86/Makefile.inc +++ b/src/arch/x86/Makefile.inc @@ -354,9 +354,9 @@ endif $(objcbfs)/romstage_null.debug: $$(romstage-objs) $(objgenerated)/romstage_null.ld @printf " LINK $(subst $(obj)/,,$(@))\n" ifeq ($(CONFIG_COMPILER_LLVM_CLANG),y) - $(LD) -nostdlib -nostartfiles -static -o $@ -L$(obj) $(romstage-objs) -T $(objgenerated)/romstage_null.ld + $(LD) -nostdlib -nostartfiles -static -o $@ -L$(obj) --wrap __divdi3 --wrap __udivdi3 --wrap __moddi3 --wrap __umoddi3 --start-group $(romstage-objs) $(LIBGCC_FILE_NAME) --end-group -T $(objgenerated)/romstage_null.ld else - $(CC) -nostdlib -nostartfiles -static -o $@ -L$(obj) -T $(objgenerated)/romstage_null.ld $(romstage-objs) + $(CC) -nostdlib -nostartfiles -static -o $@ -L$(obj) -T $(objgenerated)/romstage_null.ld -Wl,--wrap,__divdi3 -Wl,--wrap,__udivdi3 -Wl,--wrap,__moddi3 -Wl,--wrap,__umoddi3 -Wl,--start-group $(romstage-objs) $(LIBGCC_FILE_NAME) -Wl,--end-group endif $(NM) $@ | grep -q " [DdBb] "; if [ $$? -eq 0 ]; then \ echo "Forbidden global variables in romstage:"; \ @@ -366,9 +366,9 @@ endif $(objcbfs)/romstage_xip.debug: $$(romstage-objs) $(objgenerated)/romstage_xip.ld @printf " LINK $(subst $(obj)/,,$(@))\n" ifeq ($(CONFIG_COMPILER_LLVM_CLANG),y) - $(LD) -nostdlib -nostartfiles -static -o $@ -L$(obj) $(romstage-objs) -T $(objgenerated)/romstage_xip.ld + $(LD) -nostdlib -nostartfiles -static -o $@ -L$(obj) --wrap __divdi3 --wrap __udivdi3 --wrap __moddi3 --wrap __umoddi3 --start-group $(romstage-objs) $(LIBGCC_FILE_NAME) --end-group -T $(objgenerated)/romstage_xip.ld else - $(CC) -nostdlib -nostartfiles -static -o $@ -L$(obj) -T $(objgenerated)/romstage_xip.ld $(romstage-objs) + $(CC) -nostdlib -nostartfiles -static -o $@ -L$(obj) -T $(objgenerated)/romstage_xip.ld -Wl,--wrap,__divdi3 -Wl,--wrap,__udivdi3 -Wl,--wrap,__moddi3 -Wl,--wrap,__umoddi3 -Wl,--start-group $(romstage-objs) $(LIBGCC_FILE_NAME) -Wl,--end-group endif $(objgenerated)/romstage_null.ld: $$(ldscripts) $(obj)/ldoptions diff --git a/src/arch/x86/include/div64.h b/src/arch/x86/include/div64.h deleted file mode 100644 index bbc9921d29..0000000000 --- a/src/arch/x86/include/div64.h +++ /dev/null @@ -1,30 +0,0 @@ -#ifndef __I386_DIV64 -#define __I386_DIV64 - -/* - * do_div() is NOT a C function. It wants to return - * two values (the quotient and the remainder), but - * since that doesn't work very well in C, what it - * does is: - * - * - modifies the 64-bit dividend _in_place_ - * - returns the 32-bit remainder - * - * This ends up being the most efficient "calling - * convention" on x86. - */ -#define do_div(n,base) ({ \ - unsigned long __upper, __low, __high, __mod, __base; \ - __base = (base); \ - asm("":"=a" (__low), "=d" (__high):"A" (n)); \ - __upper = __high; \ - if (__high) { \ - __upper = __high % (__base); \ - __high = __high / (__base); \ - } \ - asm("divl %2":"=a" (__low), "=d" (__mod):"rm" (__base), "0" (__low), "1" (__upper)); \ - asm("":"=A" (n):"a" (__low),"d" (__high)); \ - __mod; \ -}) - -#endif |