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| author | Richard Stallman <rms@gnu.org> | 1992-07-05 21:11:08 +0000 |
|---|---|---|
| committer | Richard Stallman <rms@gnu.org> | 1992-07-05 21:11:08 +0000 |
| commit | d3d6669e17de7aa0c7d5bf32954fc1fa7d70606e (patch) | |
| tree | dc1a1d98590101682949de183ae823dc2f7ccbeb | |
| parent | cdefd0d28a14c373ca18ea534bab5e69588ede50 (diff) | |
| download | gcc-d3d6669e17de7aa0c7d5bf32954fc1fa7d70606e.zip gcc-d3d6669e17de7aa0c7d5bf32954fc1fa7d70606e.tar.gz gcc-d3d6669e17de7aa0c7d5bf32954fc1fa7d70606e.tar.bz2 | |
(addsi3): Code generation improvements (whether to use movab).
From-SVN: r1448
| -rw-r--r-- | gcc/config/vax/vax.md | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/gcc/config/vax/vax.md b/gcc/config/vax/vax.md index 5c3e03a..93e9250 100644 --- a/gcc/config/vax/vax.md +++ b/gcc/config/vax/vax.md @@ -516,6 +516,19 @@ addf2 %1,%0 addf3 %1,%2,%0") +/* The space-time-opcode tradeoffs for addition vary by model of VAX. + + On a VAX 3 "movab (r1)[r2],r3" is faster than "addl3 r1,r2,r3", + but it not faster on other models. + + "movab #(r1),r2" is usually shorter than "addl3 #,r1,r2", and is + faster on a VAX 3, but some VAXes (e.g. VAX 9000) will stall if + a register is used in an address too soon after it is set. + Compromise by using movab only when it is shorter than the add + or the base register in the address is one of sp, ap, and fp, + which are not modified very often. */ + + (define_insn "addsi3" [(set (match_operand:SI 0 "general_operand" "=g") (plus:SI (match_operand:SI 1 "general_operand" "g") @@ -534,23 +547,37 @@ return \"subl2 $%n2,%0\"; if (GET_CODE (operands[2]) == CONST_INT && (unsigned) INTVAL (operands[2]) >= 64 - && GET_CODE (operands[1]) == REG) + && GET_CODE (operands[1]) == REG + && ((INTVAL (operands[2]) < 32767 && INTVAL (operands[2]) > -32768) + || REGNO (operands[1]) > 11)) return \"movab %c2(%1),%0\"; return \"addl2 %2,%0\"; } if (rtx_equal_p (operands[0], operands[2])) return \"addl2 %1,%0\"; + + if (GET_CODE (operands[2]) == CONST_INT + && INTVAL (operands[2]) < 32767 + && INTVAL (operands[2]) > -32768 + && GET_CODE (operands[1]) == REG + && push_operand (operands[0], SImode)) + return \"pushab %c2(%1)\"; + if (GET_CODE (operands[2]) == CONST_INT && (unsigned) (- INTVAL (operands[2])) < 64) return \"subl3 $%n2,%1,%0\"; + if (GET_CODE (operands[2]) == CONST_INT && (unsigned) INTVAL (operands[2]) >= 64 - && GET_CODE (operands[1]) == REG) - { - if (push_operand (operands[0], SImode)) - return \"pushab %c2(%1)\"; - return \"movab %c2(%1),%0\"; - } + && GET_CODE (operands[1]) == REG + && ((INTVAL (operands[2]) < 32767 && INTVAL (operands[2]) > -32768) + || REGNO (operands[1]) > 11)) + return \"movab %c2(%1),%0\"; + + /* Add this if using gcc on a VAX 3xxx: + if (REG_P (operands[1]) && REG_P (operands[2])) + return \"movab (%1)[%2],%0\"; + */ return \"addl3 %1,%2,%0\"; }") |