Denis Chertykov schrieb: > 2011/9/22 Georg-Johann Lay <a...@gjlay.de>: >> This patch adds the PLUS part to fix the PR. >> >> addsi3 has a 8-bit scratch register now so that constants that are not >> covered >> by the constraints won't force a reload of the constant. >> >> The output routine tries adding the constant and subtracting the negated >> constant and then chooses the shortest sequence. Moreover, if the lower >> bytes >> of the constant are zero, there is no need to add them. >> >> Besides that, the patch adds some add-and-zero-extend patterns. >> >> Passed without regressions. > > > Why you removed immediate operand from subsi3: > > (define_insn "subsi3" > - [(set (match_operand:SI 0 "register_operand" "=r,d") > - (minus:SI (match_operand:SI 1 "register_operand" "0,0") > - (match_operand:SI 2 "nonmemory_operand" "r,i")))] > + [(set (match_operand:SI 0 "register_operand" "=r") > + (minus:SI (match_operand:SI 1 "register_operand" "0") > + (match_operand:SI 2 "register_operand" "r")))] > "" > - "@ > - sub %0,%2\;sbc %B0,%B2\;sbc %C0,%C2\;sbc %D0,%D2 > - subi %A0,lo8(%2)\;sbci %B0,hi8(%2)\;sbci %C0,hlo8(%2)\;sbci > %D0,hhi8(%2)" > - [(set_attr "length" "4,4") > - (set_attr "cc" "set_czn,set_czn")]) > + "sub %0,%2\;sbc %B0,%B2\;sbc %C0,%C2\;sbc %D0,%D2" > + [(set_attr "length" "4") > + (set_attr "cc" "set_czn")])
A = B - const is canonizalized to A = B + (-const) For compile time constants. And for SImode there are no symbols so that the immediate part of memory_operand is dead code and I cleaned it up. > Denis. Johann
