For thumb1 use move + add instructions for immediate move [256-510]. Following is a complete range if combine an imm mov with listed instructions. Among them, lsls and neg have already been implemented. The only missing opportunity is add, in which I enabled in this patch. Others are replicated with lsls or neg.
1. Result imm range with 16bit movs Insn Result imm with movs lsls [0x1-0xff] shifted by 1-31 add [256, 510] neg [-255, 0] rev [0x1000000-0xff000000] step 0x1000000 rev16 [0x100-0xff00] step 0x100 revsh [0x10000-0xff0000] step 0x10000 rsb [-255, 0] mvn [-255, 0] sub [-255, 0] sxtb [-255, 0] ChangeLog: * config/arm/constraints.md (Pe): New constraint. * config/arm/arm.md: New split for imm 256-510. Testcase: * gcc.target/arm/thumb1-imm.c: New testcase. diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md index 4f6d965..c86d42e 100644 --- a/gcc/config/arm/arm.md +++ b/gcc/config/arm/arm.md @@ -5635,6 +5635,21 @@ }" ) +;; For thumb1 split imm move [256-510] into mov [1-255] and add #255 +(define_split + [(set (match_operand:SI 0 "register_operand" "") + (match_operand:SI 1 "const_int_operand" ""))] + "TARGET_THUMB1 && satisfies_constraint_Pe (operands[1])" + [(set (match_dup 2) (match_dup 1)) + (set (match_dup 0) (plus:SI (match_dup 2) (match_dup 3)))] + " + { + operands[1] = GEN_INT (INTVAL (operands[1]) - 255); + operands[2] = can_create_pseudo_p () ? gen_reg_rtx (SImode) : operands[0]; + operands[3] = GEN_INT (255); + }" +) + ;; When generating pic, we need to load the symbol offset into a register. ;; So that the optimizer does not confuse this with a normal symbol load ;; we use an unspec. The offset will be loaded from a constant pool entry, diff --git a/gcc/config/arm/constraints.md b/gcc/config/arm/constraints.md index 3ff968b..6b59e87 100644 --- a/gcc/config/arm/constraints.md +++ b/gcc/config/arm/constraints.md @@ -30,7 +30,7 @@ ;; The following multi-letter normal constraints have been used: ;; in ARM/Thumb-2 state: Da, Db, Dc, Dn, Dl, DL, Dv, Dy, Di, Dt, Dz -;; in Thumb-1 state: Pa, Pb, Pc, Pd +;; in Thumb-1 state: Pa, Pb, Pc, Pd, Pe ;; in Thumb-2 state: Pj, PJ, Ps, Pt, Pu, Pv, Pw, Px, Py ;; The following memory constraints have been used: @@ -172,6 +172,11 @@ (and (match_code "const_int") (match_test "TARGET_THUMB1 && ival >= 0 && ival <= 7"))) +(define_constraint "Pe" + "@internal In Thumb-1 state a constant in the range 256 to +510" + (and (match_code "const_int") + (match_test "TARGET_THUMB1 && ival >= 256 && ival <= 510"))) + (define_constraint "Ps" "@internal In Thumb-2 state a constant in the range -255 to +255" (and (match_code "const_int") diff --git a/gcc/testsuite/gcc.target/arm/thumb1-imm.c b/gcc/testsuite/gcc.target/arm/thumb1-imm.c new file mode 100644 index 0000000..b47c08c --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/thumb1-imm.c @@ -0,0 +1,10 @@ +/* Check for thumb1 imm [255-510] moves. */ +/* { dg-require-effective-target arm_thumb1_ok } */ + +int f() +{ + return 257; +} + +/* { dg-final { scan-assembler-not "ldr" } } */ +