From: George Koehler Date: Tue, 29 Nov 2016 01:58:51 +0000 (-0500) Subject: Enable top and make other tweaks in plat/osxppc/descr X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=0c2b6f5;p=ack.git Enable top and make other tweaks in plat/osxppc/descr David Given made top for PowerPC. Copy the asopt phase (running top) from linuxppc to osxppc. Remove CC_ALIGN=-Vr to become compatible with Apple's gcc. Apple uses left adjustment for bitfields; the first bitfield is on the left side (the big end), not the right side. Remove unused variables C_LIB and OLD_C_LIB; the file libc-ansi.a doesn't exist. Change MACHOPT_F from -m10 to -m3. This means to use no more than 3 adds and shifts to optimize a multiply by a constant. I pick -m3 because -m4 can use too many instructions. At -m4, the compiler rewrites n * 14 as s = n << 1 (s << 3) + (0 - s) This means (n * 16 - n * 2), but even at ack -O6, the compiler doesn't rewrite (a + (0 - b)) as (a - b). The compiler emits 5 instructions: 2 of rlinmw for 2 left shifts, then addi to load 0 in a register, subf to subtract from that 0, then add. These 5 instructions cost 5 cycles on the MPC7450, using the cycle counts from mach/powerpc/ncg/table. At -m3, (n * 14) becomes 2 instructions: addi to load 14 in a register and mullw to multiply. This also costs 5 cycles (because mullw costs 4 cycles), but uses less space. --- diff --git a/plat/osxppc/descr b/plat/osxppc/descr index 130d2bd25..2a6d47871 100644 --- a/plat/osxppc/descr +++ b/plat/osxppc/descr @@ -19,12 +19,7 @@ var PLATFORM=osxppc var PLATFORMDIR={EM}/share/ack/{PLATFORM} var CPP_F=-D__unix var ALIGN=-a0:4 -a1:4 -a2:4096 -a3:4 -b0:0x129c -var C_LIB={PLATFORMDIR}/libc-ansi.a -# bitfields reversed for compatibility with (g)cc. -# XXX this is from linux386, might be wrong for osxppc -var CC_ALIGN=-Vr -var OLD_C_LIB={C_LIB} -var MACHOPT_F=-m10 +var MACHOPT_F=-m3 # var EGO_PLAT_FLAGS=-M{EM}/share/ack/ego/{ARCH}.descr # Override the setting in fe so that files compiled for osxppc can see @@ -41,6 +36,15 @@ name be stdout need .e end +name asopt + from .s + to .so + program {EM}/lib/ack/linuxppc/top + args + optimizer + stdin + stdout +end name as from .s.so to .o