Patch 1 is the mode-query problem Richard asked to split out of v1. It
has its own PR now since it has a visible effect by itself: with a
view-convert between the two permutes the pattern merges them even when
only the merged permute is unsupported, and the result is lowered
element by element (3 -> 13 instructions on x86_64 with SSE2).
Patch 2 is the fix for permutes whose inputs and results differ in
length, on top of that.
Bootstrapped and regtested on x86_64-pc-linux-gnu (-m32/-m64), no new
regressions.
Changes since v1:
- Split the can_vec_perm_const_p mode queries of the <c, c> merge into
their own patch (1/2, PR127882), with a testcase.
- 2/2: use sel0.nelts_per_input () for the merged selector.
- 2/2: the merged permute's mode is computed once (perm_mode) and the
comments no longer talk about element types.
- 2/2: reworded the comment above the <c, c> pattern: a and b have the
same length, c and d may each differ.
- 2/2: new test vec-perm-merge-wide-input-3.c covering all nine length
combinations of a/c/d for the <c, c> merge (re the sel0[sel1[i]]
question).
- Added Assisted-by: to both patches.
Igor Shevlyakov (2):
match.pd: Fix mode queries of VEC_PERM merge through view-convert
[PR127882]
middle-end: Fix VEC_PERM_EXPR merges of different-length vectors
[PR127862]
gcc/match.pd | 67 ++-
.../torture/vec-perm-merge-wide-input-1.c | 193 +++++++++
.../torture/vec-perm-merge-wide-input-2.c | 64 +++
.../torture/vec-perm-merge-wide-input-3.c | 382 ++++++++++++++++++
.../gcc.target/aarch64/sve/pr127862.c | 53 +++
.../gcc.target/aarch64/sve/pr127862_run.c | 46 +++
gcc/testsuite/gcc.target/i386/pr127882.c | 27 ++
gcc/tree-ssa-forwprop.cc | 9 +
8 files changed, 826 insertions(+), 15 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/vec-perm-merge-wide-input-1.c
create mode 100644 gcc/testsuite/gcc.dg/torture/vec-perm-merge-wide-input-2.c
create mode 100644 gcc/testsuite/gcc.dg/torture/vec-perm-merge-wide-input-3.c
create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/pr127862.c
create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/pr127862_run.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr127882.c
--
2.56.0
