Message ID | 001b01cda6f8$65c98be0$315ca3a0$@yorsh@arm.com |
---|---|
State | New |
Headers | show |
On 10/10/12 16:03, Greta Yorsh wrote: > Generate prologue using STRD when prefer_ldrd_strd is set in tune_params. > > ChangeLog > > gcc/ > > 2012-09-13 Sameera Deshpande <sameera.deshpande@arm.com> > Greta Yorsh <Greta.Yorsh@arm.com> > > * config/arm/arm.c (thumb2_emit_strd_push): New function. > (arm_expand_prologue): Use the new function. > > > 2-thumb-prolog-strd.patch.txt > > > diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c > index b3a3774..1212a93 100644 > --- a/gcc/config/arm/arm.c > +++ b/gcc/config/arm/arm.c > @@ -15737,6 +15737,126 @@ arm_output_function_epilogue (FILE *file ATTRIBUTE_UNUSED, > } > } > > +/* Generate and emit a pattern that will be recognized as STRD pattern. If even > + number of registers are being pushed, multiple STRD patterns are created for > + all register pairs. If odd number of registers are pushed, emit a > + combination of STRDs and STR for the prologue saves. */ > +static void > +thumb2_emit_strd_push (unsigned long saved_regs_mask) > +{ > + int num_regs = 0; > + int i, j; > + rtx par = NULL_RTX; > + rtx insn = NULL_RTX; > + rtx dwarf = NULL_RTX; > + rtx tmp, reg, tmp1; > + > + for (i = 0; i <= LAST_ARM_REGNUM; i++) > + if (saved_regs_mask & (1 << i)) > + num_regs++; > + > + gcc_assert (num_regs && num_regs <= 16); > + > + /* Pre-decrement the stack pointer, based on there being num_regs 4-byte > + registers to push. */ > + tmp = gen_rtx_SET (VOIDmode, > + stack_pointer_rtx, > + plus_constant (Pmode, stack_pointer_rtx, -4 * num_regs)); > + RTX_FRAME_RELATED_P (tmp) = 1; > + insn = emit_insn (tmp); > + > + /* Create sequence for DWARF info. */ > + dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (num_regs + 1)); > + > + /* RTLs cannot be shared, hence create new copy for dwarf. */ > + tmp1 = gen_rtx_SET (VOIDmode, > + stack_pointer_rtx, > + plus_constant (Pmode, stack_pointer_rtx, -4 * num_regs)); > + RTX_FRAME_RELATED_P (tmp1) = 1; > + XVECEXP (dwarf, 0, 0) = tmp1; > + > + /* Var j iterates over all the registers to gather all the registers in > + saved_regs_mask. Var i gives index of register R_j in stack frame. > + A PARALLEL RTX of register-pair is created here, so that pattern for > + STRD can be matched. If num_regs is odd, 1st register will be pushed > + using STR and remaining registers will be pushed with STRD in pairs. > + If num_regs is even, all registers are pushed with STRD in pairs. > + Hence, skip first element for odd num_regs. */ > + for (i = num_regs - 1, j = LAST_ARM_REGNUM; i >= (num_regs % 2); j--) > + if (saved_regs_mask & (1 << j)) > + { > + gcc_assert (j != SP_REGNUM); > + gcc_assert (j != PC_REGNUM); It would be better to assert at the head of the function that saved_regs_mask does not contain SP or PC, rather than checking every iteration of the loop. > + > + /* Create RTX for store. New RTX is created for dwarf as > + they are not sharable. */ > + reg = gen_rtx_REG (SImode, j); > + tmp = gen_rtx_SET (SImode, > + gen_frame_mem > + (SImode, > + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), > + reg); > + > + tmp1 = gen_rtx_SET (SImode, > + gen_frame_mem > + (SImode, > + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), > + reg); > + RTX_FRAME_RELATED_P (tmp) = 1; > + RTX_FRAME_RELATED_P (tmp1) = 1; > + > + if (((i - (num_regs % 2)) % 2) == 1) > + /* When (i - (num_regs % 2)) is odd, the RTX to be emitted is yet to > + be created. Hence create it first. The STRD pattern we are > + generating is : > + [ (SET (MEM (PLUS (SP) (NUM))) (reg_t1)) > + (SET (MEM (PLUS (SP) (NUM + 4))) (reg_t2)) ] > + were target registers need not be consecutive. */ s/were/where the/ > + par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2)); > + > + /* Register R_j is added in PARALLEL RTX. If (i - (num_regs % 2)) is > + even, the reg_j is added as 0th element and if it is odd, reg_i is > + added as 1st element of STRD pattern shown above. */ > + XVECEXP (par, 0, ((i - (num_regs % 2)) % 2)) = tmp; > + XVECEXP (dwarf, 0, (i + 1)) = tmp1; > + > + if (((i - (num_regs % 2)) % 2) == 0) > + /* When (i - (num_regs % 2)) is even, RTXs for both the registers > + to be loaded are generated in above given STRD pattern, and the > + pattern can be emitted now. */ > + emit_insn (par); > + > + i--; > + } > + > + if ((num_regs % 2) == 1) > + { > + /* If odd number of registers are pushed, generate STR pattern to store > + lone register. */ > + for (; (saved_regs_mask & (1 << j)) == 0; j--); > + > + tmp1 = gen_frame_mem (SImode, plus_constant (Pmode, > + stack_pointer_rtx, 4 * i)); > + reg = gen_rtx_REG (SImode, j); > + tmp = gen_rtx_SET (SImode, tmp1, reg); > + RTX_FRAME_RELATED_P (tmp) = 1; > + > + emit_insn (tmp); > + > + tmp1 = gen_rtx_SET (SImode, > + gen_frame_mem > + (SImode, > + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), > + reg); > + RTX_FRAME_RELATED_P (tmp1) = 1; > + XVECEXP (dwarf, 0, (i + 1)) = tmp1; > + } > + > + add_reg_note (insn, REG_FRAME_RELATED_EXPR, dwarf); > + RTX_FRAME_RELATED_P (insn) = 1; > + return; > +} > + > /* Generate and emit an insn that we will recognize as a push_multi. > Unfortunately, since this insn does not reflect very well the actual > semantics of the operation, we need to annotate the insn for the benefit > @@ -16661,8 +16781,25 @@ arm_expand_prologue (void) > saved_regs += frame; > } > } > - insn = emit_multi_reg_push (live_regs_mask); > - RTX_FRAME_RELATED_P (insn) = 1; > + > + if (current_tune->prefer_ldrd_strd > + && !optimize_function_for_size_p (cfun)) > + { > + if (TARGET_THUMB2) > + { > + thumb2_emit_strd_push (live_regs_mask); > + } > + else > + { > + insn = emit_multi_reg_push (live_regs_mask); > + RTX_FRAME_RELATED_P (insn) = 1; > + } > + } > + else > + { > + insn = emit_multi_reg_push (live_regs_mask); > + RTX_FRAME_RELATED_P (insn) = 1; > + } > } > > if (! IS_VOLATILE (func_type)) > Otherwise OK. R.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index b3a3774..1212a93 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -15737,6 +15737,126 @@ arm_output_function_epilogue (FILE *file ATTRIBUTE_UNUSED, } } +/* Generate and emit a pattern that will be recognized as STRD pattern. If even + number of registers are being pushed, multiple STRD patterns are created for + all register pairs. If odd number of registers are pushed, emit a + combination of STRDs and STR for the prologue saves. */ +static void +thumb2_emit_strd_push (unsigned long saved_regs_mask) +{ + int num_regs = 0; + int i, j; + rtx par = NULL_RTX; + rtx insn = NULL_RTX; + rtx dwarf = NULL_RTX; + rtx tmp, reg, tmp1; + + for (i = 0; i <= LAST_ARM_REGNUM; i++) + if (saved_regs_mask & (1 << i)) + num_regs++; + + gcc_assert (num_regs && num_regs <= 16); + + /* Pre-decrement the stack pointer, based on there being num_regs 4-byte + registers to push. */ + tmp = gen_rtx_SET (VOIDmode, + stack_pointer_rtx, + plus_constant (Pmode, stack_pointer_rtx, -4 * num_regs)); + RTX_FRAME_RELATED_P (tmp) = 1; + insn = emit_insn (tmp); + + /* Create sequence for DWARF info. */ + dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (num_regs + 1)); + + /* RTLs cannot be shared, hence create new copy for dwarf. */ + tmp1 = gen_rtx_SET (VOIDmode, + stack_pointer_rtx, + plus_constant (Pmode, stack_pointer_rtx, -4 * num_regs)); + RTX_FRAME_RELATED_P (tmp1) = 1; + XVECEXP (dwarf, 0, 0) = tmp1; + + /* Var j iterates over all the registers to gather all the registers in + saved_regs_mask. Var i gives index of register R_j in stack frame. + A PARALLEL RTX of register-pair is created here, so that pattern for + STRD can be matched. If num_regs is odd, 1st register will be pushed + using STR and remaining registers will be pushed with STRD in pairs. + If num_regs is even, all registers are pushed with STRD in pairs. + Hence, skip first element for odd num_regs. */ + for (i = num_regs - 1, j = LAST_ARM_REGNUM; i >= (num_regs % 2); j--) + if (saved_regs_mask & (1 << j)) + { + gcc_assert (j != SP_REGNUM); + gcc_assert (j != PC_REGNUM); + + /* Create RTX for store. New RTX is created for dwarf as + they are not sharable. */ + reg = gen_rtx_REG (SImode, j); + tmp = gen_rtx_SET (SImode, + gen_frame_mem + (SImode, + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), + reg); + + tmp1 = gen_rtx_SET (SImode, + gen_frame_mem + (SImode, + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), + reg); + RTX_FRAME_RELATED_P (tmp) = 1; + RTX_FRAME_RELATED_P (tmp1) = 1; + + if (((i - (num_regs % 2)) % 2) == 1) + /* When (i - (num_regs % 2)) is odd, the RTX to be emitted is yet to + be created. Hence create it first. The STRD pattern we are + generating is : + [ (SET (MEM (PLUS (SP) (NUM))) (reg_t1)) + (SET (MEM (PLUS (SP) (NUM + 4))) (reg_t2)) ] + were target registers need not be consecutive. */ + par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2)); + + /* Register R_j is added in PARALLEL RTX. If (i - (num_regs % 2)) is + even, the reg_j is added as 0th element and if it is odd, reg_i is + added as 1st element of STRD pattern shown above. */ + XVECEXP (par, 0, ((i - (num_regs % 2)) % 2)) = tmp; + XVECEXP (dwarf, 0, (i + 1)) = tmp1; + + if (((i - (num_regs % 2)) % 2) == 0) + /* When (i - (num_regs % 2)) is even, RTXs for both the registers + to be loaded are generated in above given STRD pattern, and the + pattern can be emitted now. */ + emit_insn (par); + + i--; + } + + if ((num_regs % 2) == 1) + { + /* If odd number of registers are pushed, generate STR pattern to store + lone register. */ + for (; (saved_regs_mask & (1 << j)) == 0; j--); + + tmp1 = gen_frame_mem (SImode, plus_constant (Pmode, + stack_pointer_rtx, 4 * i)); + reg = gen_rtx_REG (SImode, j); + tmp = gen_rtx_SET (SImode, tmp1, reg); + RTX_FRAME_RELATED_P (tmp) = 1; + + emit_insn (tmp); + + tmp1 = gen_rtx_SET (SImode, + gen_frame_mem + (SImode, + plus_constant (Pmode, stack_pointer_rtx, 4 * i)), + reg); + RTX_FRAME_RELATED_P (tmp1) = 1; + XVECEXP (dwarf, 0, (i + 1)) = tmp1; + } + + add_reg_note (insn, REG_FRAME_RELATED_EXPR, dwarf); + RTX_FRAME_RELATED_P (insn) = 1; + return; +} + /* Generate and emit an insn that we will recognize as a push_multi. Unfortunately, since this insn does not reflect very well the actual semantics of the operation, we need to annotate the insn for the benefit @@ -16661,8 +16781,25 @@ arm_expand_prologue (void) saved_regs += frame; } } - insn = emit_multi_reg_push (live_regs_mask); - RTX_FRAME_RELATED_P (insn) = 1; + + if (current_tune->prefer_ldrd_strd + && !optimize_function_for_size_p (cfun)) + { + if (TARGET_THUMB2) + { + thumb2_emit_strd_push (live_regs_mask); + } + else + { + insn = emit_multi_reg_push (live_regs_mask); + RTX_FRAME_RELATED_P (insn) = 1; + } + } + else + { + insn = emit_multi_reg_push (live_regs_mask); + RTX_FRAME_RELATED_P (insn) = 1; + } } if (! IS_VOLATILE (func_type))