diff options
| author | Richard Sandiford <richard.sandiford@arm.com> | 2020-12-17 00:15:06 +0000 |
|---|---|---|
| committer | Richard Sandiford <richard.sandiford@arm.com> | 2020-12-17 00:15:06 +0000 |
| commit | 6059a3dd084d157759309357e5a52f8a8cc504c1 (patch) | |
| tree | 995df859e09f7f248c362584f2e76cd62bcb11c4 /gcc | |
| parent | f48b51496d08de2aabc5ed1deb45e5517333662c (diff) | |
| download | gcc-6059a3dd084d157759309357e5a52f8a8cc504c1.zip gcc-6059a3dd084d157759309357e5a52f8a8cc504c1.tar.gz gcc-6059a3dd084d157759309357e5a52f8a8cc504c1.tar.bz2 | |
recog: Add a validate_change_xveclen function
A later patch wants to be able to use the validate_change machinery
to reduce the XVECLEN of a PARALLEL. This should be more efficient
than allocating a separate PARALLEL at a possibly distant memory
location, especially since the new PARALLEL would be garbage rtl if
the new pattern turns out not to match. Combine already pulls this
trick with SUBST_INT.
This patch adds a general helper for doing that.
gcc/
* recog.h (validate_change_xveclen): Declare.
* recog.c (change_t::old_len): New field.
(validate_change_1): Add a new_len parameter. Conditionally
replace the XVECLEN of an rtx, avoiding single-element PARALLELs.
(validate_change_xveclen): New function.
(cancel_changes): Undo changes made by validate_change_xveclen.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/recog.c | 41 | ||||
| -rw-r--r-- | gcc/recog.h | 1 |
2 files changed, 36 insertions, 6 deletions
diff --git a/gcc/recog.c b/gcc/recog.c index 2d93416..65125b8 100644 --- a/gcc/recog.c +++ b/gcc/recog.c @@ -183,6 +183,7 @@ struct change_t { rtx object; int old_code; + int old_len; bool unshare; rtx *loc; rtx old; @@ -194,8 +195,10 @@ static int changes_allocated; static int num_changes = 0; /* Validate a proposed change to OBJECT. LOC is the location in the rtl - at which NEW_RTX will be placed. If OBJECT is zero, no validation is done, - the change is simply made. + at which NEW_RTX will be placed. If NEW_LEN is >= 0, XVECLEN (NEW_RTX, 0) + will also be changed to NEW_LEN, which is no greater than the current + XVECLEN. If OBJECT is zero, no validation is done, the change is + simply made. Two types of objects are supported: If OBJECT is a MEM, memory_address_p will be called with the address and mode as parameters. If OBJECT is @@ -212,14 +215,25 @@ static int num_changes = 0; Otherwise, perform the change and return 1. */ static bool -validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, bool unshare) +validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, + bool unshare, int new_len = -1) { rtx old = *loc; - if (old == new_rtx || rtx_equal_p (old, new_rtx)) + /* Single-element parallels aren't valid and won't match anything. + Replace them with the single element. */ + if (new_len == 1 && GET_CODE (new_rtx) == PARALLEL) + { + new_rtx = XVECEXP (new_rtx, 0, 0); + new_len = -1; + } + + if ((old == new_rtx || rtx_equal_p (old, new_rtx)) + && (new_len < 0 || XVECLEN (new_rtx, 0) == new_len)) return 1; - gcc_assert (in_group != 0 || num_changes == 0); + gcc_assert ((in_group != 0 || num_changes == 0) + && (new_len < 0 || new_rtx == *loc)); *loc = new_rtx; @@ -239,8 +253,12 @@ validate_change_1 (rtx object, rtx *loc, rtx new_rtx, bool in_group, bool unshar changes[num_changes].object = object; changes[num_changes].loc = loc; changes[num_changes].old = old; + changes[num_changes].old_len = (new_len >= 0 ? XVECLEN (new_rtx, 0) : -1); changes[num_changes].unshare = unshare; + if (new_len >= 0) + XVECLEN (new_rtx, 0) = new_len; + if (object && !MEM_P (object)) { /* Set INSN_CODE to force rerecognition of insn. Save old code in @@ -278,6 +296,14 @@ validate_unshare_change (rtx object, rtx *loc, rtx new_rtx, bool in_group) return validate_change_1 (object, loc, new_rtx, in_group, true); } +/* Change XVECLEN (*LOC, 0) to NEW_LEN. OBJECT, IN_GROUP and the return + value are as for validate_change_1. */ + +bool +validate_change_xveclen (rtx object, rtx *loc, int new_len, bool in_group) +{ + return validate_change_1 (object, loc, *loc, in_group, false, new_len); +} /* Keep X canonicalized if some changes have made it non-canonical; only modifies the operands of X, not (for example) its code. Simplifications @@ -541,7 +567,10 @@ cancel_changes (int num) they were made. */ for (i = num_changes - 1; i >= num; i--) { - *changes[i].loc = changes[i].old; + if (changes[i].old_len >= 0) + XVECLEN (*changes[i].loc, 0) = changes[i].old_len; + else + *changes[i].loc = changes[i].old; if (changes[i].object && !MEM_P (changes[i].object)) INSN_CODE (changes[i].object) = changes[i].old_code; } diff --git a/gcc/recog.h b/gcc/recog.h index d87456c..e152e2b 100644 --- a/gcc/recog.h +++ b/gcc/recog.h @@ -88,6 +88,7 @@ extern int check_asm_operands (rtx); extern int asm_operand_ok (rtx, const char *, const char **); extern bool validate_change (rtx, rtx *, rtx, bool); extern bool validate_unshare_change (rtx, rtx *, rtx, bool); +extern bool validate_change_xveclen (rtx, rtx *, int, bool); extern bool canonicalize_change_group (rtx_insn *insn, rtx x); extern int insn_invalid_p (rtx_insn *, bool); extern int verify_changes (int); |