For predictable semantics propagate the mode from operands referred by FP substitutions to the `const_double_zero' expressions used with the associated condition code calculation, resulting in the following update to insn-emit.c code produced for the `pdp11-aout' target (with machine description line numbering change noise removed):
@@ -1514,7 +1514,7 @@ gen_rtx_COMPARE (CCmode, gen_rtx_ABS (DFmode, operand1), - CONST_DOUBLE_ATOF ("0", VOIDmode))), + CONST_DOUBLE_ATOF ("0", DFmode))), gen_rtx_SET (operand0, gen_rtx_ABS (DFmode, copy_rtx (operand1))))); @@ -1555,7 +1555,7 @@ gen_rtx_COMPARE (CCmode, gen_rtx_NEG (DFmode, operand1), - CONST_DOUBLE_ATOF ("0", VOIDmode))), + CONST_DOUBLE_ATOF ("0", DFmode))), gen_rtx_SET (operand0, gen_rtx_NEG (DFmode, copy_rtx (operand1))))); @@ -1790,7 +1790,7 @@ gen_rtx_MULT (DFmode, operand1, operand2), - CONST_DOUBLE_ATOF ("0", VOIDmode))), + CONST_DOUBLE_ATOF ("0", DFmode))), gen_rtx_SET (operand0, gen_rtx_MULT (DFmode, copy_rtx (operand1), @@ -1942,7 +1942,7 @@ gen_rtx_DIV (DFmode, operand1, operand2), - CONST_DOUBLE_ATOF ("0", VOIDmode))), + CONST_DOUBLE_ATOF ("0", DFmode))), gen_rtx_SET (operand0, gen_rtx_DIV (DFmode, copy_rtx (operand1), Provide a new iterator to provide copies of FP substitutions across the FP modes supported as the substitutions now need to match the mode of the operands. gcc/ * config/pdp11/pdp11.md (PDPfp): New mode iterator. (fcc_cc, fcc_ccnz): Use it. Add mode to `const_double_zero' and operands. --- gcc/config/pdp11/pdp11.md | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) gcc-pdp11-const-double-zero-mode.diff Index: gcc/gcc/config/pdp11/pdp11.md =================================================================== --- gcc.orig/gcc/config/pdp11/pdp11.md +++ gcc/gcc/config/pdp11/pdp11.md @@ -82,6 +82,8 @@ (define_code_iterator SHF [ashift ashiftrt lshiftrt]) +(define_mode_iterator PDPfp [SF DF]) + ;; Substitution to turn a CC clobber into a CC setter. We have four of ;; these: for CCmode vs. CCNZmode, and for CC_REGNUM vs. FCC_REGNUM. (define_subst "cc_cc" @@ -101,19 +103,19 @@ (set (match_dup 0) (match_dup 1))]) (define_subst "fcc_cc" - [(set (match_operand 0 "") (match_operand 1 "")) + [(set (match_operand:PDPfp 0 "") (match_operand:PDPfp 1 "")) (clobber (reg FCC_REGNUM))] "" [(set (reg:CC FCC_REGNUM) - (compare:CC (match_dup 1) (const_double_zero))) + (compare:CC (match_dup 1) (const_double_zero:PDPfp))) (set (match_dup 0) (match_dup 1))]) (define_subst "fcc_ccnz" - [(set (match_operand 0 "") (match_operand 1 "")) + [(set (match_operand:PDPfp 0 "") (match_operand:PDPfp 1 "")) (clobber (reg FCC_REGNUM))] "" [(set (reg:CCNZ FCC_REGNUM) - (compare:CCNZ (match_dup 1) (const_double_zero))) + (compare:CCNZ (match_dup 1) (const_double_zero:PDPfp))) (set (match_dup 0) (match_dup 1))]) (define_subst_attr "cc_cc" "cc_cc" "_nocc" "_cc")