This patch allows setting REG_EQUAL for ZERO_EXTRACT and handle that in cse (where the src for the ZERO_EXTRACT needs to be calculated)
Thanks, Kugan 2015-06-26 Kugan Vivekanandarajah <kug...@linaro.org> * cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT. * emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set REG_EQUAL note.
>From 75e746e559ffd21b25542b3db627e3b318118569 Mon Sep 17 00:00:00 2001 From: Kugan Vivekanandarajah <kugan.vivekanandara...@linaro.org> Date: Fri, 26 Jun 2015 17:12:07 +1000 Subject: [PATCH 1/2] Allow adding REG_EQUAL for ZERO_EXTRACT --- gcc/ChangeLog | 6 ++++++ gcc/cse.c | 41 ++++++++++++++++++++++++++++++++++++++++- gcc/emit-rtl.c | 3 ++- 3 files changed, 48 insertions(+), 2 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 080aa39..d4a73d6 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2015-06-26 Kugan Vivekanandarajah <kug...@linaro.org> + + * cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT. + * emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set + REG_EQUAL note. + 2015-06-25 H.J. Lu <hongjiu...@intel.com> * gentarget-def.c (def_target_insn): Cast return of strtol to diff --git a/gcc/cse.c b/gcc/cse.c index 100c9c8..8add651 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -4531,8 +4531,47 @@ cse_insn (rtx_insn *insn) if (n_sets == 1 && REG_NOTES (insn) != 0 && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0 && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)) + || GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)) - src_eqv = copy_rtx (XEXP (tem, 0)); + { + src_eqv = copy_rtx (XEXP (tem, 0)); + + /* If DEST is of the form ZERO_EXTACT, as in: + (set (zero_extract:SI (reg:SI 119) + (const_int 16 [0x10]) + (const_int 16 [0x10])) + (const_int 51154 [0xc7d2])) + REG_EQUAL note will specify the value of register (reg:SI 119) at this + point. Note that this is different from SRC_EQV. We can however + calculate SRC_EQV with the position and width of ZERO_EXTRACT. */ + if (GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT) + { + if (CONST_INT_P (src_eqv) + && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 1)) + && CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 2))) + { + rtx dest_reg = XEXP (SET_DEST (sets[0].rtl), 0); + rtx width = XEXP (SET_DEST (sets[0].rtl), 1); + rtx pos = XEXP (SET_DEST (sets[0].rtl), 2); + HOST_WIDE_INT val = INTVAL (src_eqv); + HOST_WIDE_INT mask; + unsigned int shift; + if (BITS_BIG_ENDIAN) + shift = GET_MODE_PRECISION (GET_MODE (dest_reg)) + - INTVAL (pos) - INTVAL (width); + else + shift = INTVAL (pos); + if (INTVAL (width) == HOST_BITS_PER_WIDE_INT) + mask = ~(HOST_WIDE_INT) 0; + else + mask = ((HOST_WIDE_INT) 1 << INTVAL (width)) - 1; + val = (val >> shift) & mask; + src_eqv = GEN_INT (val); + } + else + src_eqv = 0; + } + } /* Set sets[i].src_elt to the class each source belongs to. Detect assignments from or to volatile things diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c index e7f7eab..cb891b1 100644 --- a/gcc/emit-rtl.c +++ b/gcc/emit-rtl.c @@ -5228,7 +5228,8 @@ set_for_reg_notes (rtx insn) reg = SET_DEST (pat); /* Notes apply to the contents of a STRICT_LOW_PART. */ - if (GET_CODE (reg) == STRICT_LOW_PART) + if (GET_CODE (reg) == STRICT_LOW_PART + || GET_CODE (reg) == ZERO_EXTRACT) reg = XEXP (reg, 0); /* Check that we have a register. */ -- 1.9.1