nir: Check against combined alignment in nir_lower_mem_access_bit_sizes

Checking against align_mul is insufficient if align_offset > 0.  We need
to check against the combined alignment instead.

Fixes: 2e2d7803c7f1 ("nir: Add a load/store bit size lowering pass")
Reviewed-by: M Henning <drawoc@darkrefraction.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21524>

diff --git a/src/compiler/nir/nir_lower_mem_access_bit_sizes.c b/src/compiler/nir/nir_lower_mem_access_bit_sizes.c
index c8a494d..d22967e 100644 (file)
--- a/src/compiler/nir/nir_lower_mem_access_bit_sizes.c
+++ b/src/compiler/nir/nir_lower_mem_access_bit_sizes.c
@@ -82,6 +82,7 @@ lower_mem_load(nir_builder *b, nir_intrinsic_instr *intrin,
    const unsigned bytes_read = num_components * (bit_size / 8);
    const uint32_t align_mul = nir_intrinsic_align_mul(intrin);
    const uint32_t align_offset = nir_intrinsic_align_offset(intrin);
+   const uint32_t align = nir_intrinsic_align(intrin);
    nir_src *offset_src = nir_get_io_offset_src(intrin);
    const bool offset_is_const = nir_src_is_const(*offset_src);
    assert(offset_src->is_ssa);
@@ -96,7 +97,7 @@ lower_mem_load(nir_builder *b, nir_intrinsic_instr *intrin,
    assert(util_is_power_of_two_nonzero(requested.align_mul));
    if (requested.num_components == num_components &&
        requested.bit_size == bit_size &&
-       requested.align_mul <= align_mul)
+       requested.align_mul <= align)
       return false;
 
    /* Otherwise, we have to break it into chunks.  We could end up with as
@@ -208,6 +209,7 @@ lower_mem_store(nir_builder *b, nir_intrinsic_instr *intrin,
    const unsigned bytes_written = num_components * byte_size;
    const uint32_t align_mul = nir_intrinsic_align_mul(intrin);
    const uint32_t align_offset = nir_intrinsic_align_offset(intrin);
+   const uint32_t align = nir_intrinsic_align(intrin);
    nir_src *offset_src = nir_get_io_offset_src(intrin);
    const bool offset_is_const = nir_src_is_const(*offset_src);
    assert(offset_src->is_ssa);
@@ -225,7 +227,7 @@ lower_mem_store(nir_builder *b, nir_intrinsic_instr *intrin,
    assert(util_is_power_of_two_nonzero(requested.align_mul));
    if (requested.num_components == num_components &&
        requested.bit_size == bit_size &&
-       requested.align_mul <= align_mul &&
+       requested.align_mul <= align &&
        writemask == BITFIELD_MASK(num_components))
       return false;