From 85ddb3994b49715fb52c3235cfca33c29d868dda Mon Sep 17 00:00:00 2001 From: Richard Stallman Date: Sat, 31 Oct 1992 21:17:49 +0000 Subject: [PATCH] (output_move_double): Undo 10/25 change. (output_move_double): Undo 10/25 change. Handle case where part of a dest reg is used in a src mem rtx, without using stack. From-SVN: r2665 --- gcc/config/i386/i386.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index c9265c6a812..fd2f1f92f8c 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -42,7 +42,6 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #define AT_BP(mode) (gen_rtx (MEM, (mode), frame_pointer_rtx)) -extern rtx gen_push_operand (); extern FILE *asm_out_file; extern char *strcat (); @@ -244,7 +243,7 @@ output_move_double (operands) enum {REGOP, OFFSOP, MEMOP, PUSHOP, POPOP, CNSTOP, RNDOP } optype0, optype1; rtx latehalf[2]; rtx addreg0 = 0, addreg1 = 0; - rtx pop_after = 0; + int dest_overlapped_low = 0; /* First classify both operands. */ @@ -355,13 +354,29 @@ output_move_double (operands) operands[1] = latehalf[1]; /* For (set (reg:DI N) (mem:DI ... (reg:SI N) ...)), - push the first word on the stack, and pop it off afterward. */ + if the upper part of reg N does not appear in the MEM, arrange to + emit the move late-half first. Otherwise, compute the MEM address + into the upper part of N and use that as a pointer to the memory + operand. */ if (optype0 == REGOP - && refers_to_regno_p (REGNO (operands[0]), REGNO (operands[0]) + 1, - operands[1], 0)) + && (optype1 == OFFSOP || optype1 == MEMOP)) { - pop_after = operands[0]; - operands[0] = gen_rtx (MEM, SImode, gen_push_operand ()); + if (reg_mentioned_p (operands[0], XEXP (operands[1], 0)) + && reg_mentioned_p (latehalf[0], XEXP (operands[1], 0))) + { + /* If both halves of dest are used in the src memory address, + compute the address into latehalf of dest. */ + rtx xops[2]; + xops[0] = latehalf[0]; + xops[1] = XEXP (operands[1], 0); + output_asm_insn (AS2 (lea%L0,%a1,%0), xops); + operands[1] = gen_rtx (MEM, DImode, latehalf[0]); + latehalf[1] = adj_offsettable_operand (operands[1], 4); + } + else if (reg_mentioned_p (operands[0], XEXP (operands[1], 0))) + /* If the low half of dest is mentioned in the source memory + address, the arrange to emit the move late half first. */ + dest_overlapped_low = 1; } /* If one or both operands autodecrementing, @@ -374,7 +389,8 @@ output_move_double (operands) if (optype0 == PUSHOP || optype1 == PUSHOP || (optype0 == REGOP && optype1 == REGOP - && REGNO (operands[0]) == REGNO (latehalf[1]))) + && REGNO (operands[0]) == REGNO (latehalf[1])) + || dest_overlapped_low) { /* Make any unoffsettable addresses point at high-numbered word. */ if (addreg0) @@ -414,11 +430,6 @@ output_move_double (operands) if (addreg1) asm_add (-4, addreg1); - /* If we diverted a word to the stack, pop it now - to the proper register. */ - if (pop_after != 0) - output_asm_insn ("pop%L0 %0", &pop_after); - return ""; } -- 2.30.2