nir: add amul instruction

Used for address/offset calculation (ie. array derefs), where we can
potentially use less than 32b for the multiply of array idx by element
size.  For backends that support `imul24`, this gives a lowering pass
an easy way to find multiplies that potentially can be converted to
`imul24`.

Signed-off-by: Rob Clark <[email protected]>
Reviewed-by: Kristian H. Kristensen <[email protected]>
Reviewed-by: Eduardo Lima Mitev <[email protected]>

1 files changed, 15 insertions, 1 deletions

diff --git a/src/compiler/nir/nir_builder.h b/src/compiler/nir/nir_builder.h
index cad0e133cbf..5714ea08ed2 100644
--- a/src/compiler/nir/nir_builder.h
+++ b/src/compiler/nir/nir_builder.h
@@ -646,7 +646,7 @@ nir_iadd_imm(nir_builder *build, nir_ssa_def *x, uint64_t y)
 }
 
 static inline nir_ssa_def *
-nir_imul_imm(nir_builder *build, nir_ssa_def *x, uint64_t y)
+_nir_mul_imm(nir_builder *build, nir_ssa_def *x, uint64_t y, bool amul)
 {
    assert(x->bit_size <= 64);
    if (x->bit_size < 64)
@@ -658,12 +658,26 @@ nir_imul_imm(nir_builder *build, nir_ssa_def *x, uint64_t y)
       return x;
    } else if (util_is_power_of_two_or_zero64(y)) {
       return nir_ishl(build, x, nir_imm_int(build, ffsll(y) - 1));
+   } else if (amul) {
+      return nir_amul(build, x, nir_imm_intN_t(build, y, x->bit_size));
    } else {
       return nir_imul(build, x, nir_imm_intN_t(build, y, x->bit_size));
    }
 }
 
 static inline nir_ssa_def *
+nir_imul_imm(nir_builder *build, nir_ssa_def *x, uint64_t y)
+{
+   return _nir_mul_imm(build, x, y, false);
+}
+
+static inline nir_ssa_def *
+nir_amul_imm(nir_builder *build, nir_ssa_def *x, uint64_t y)
+{
+   return _nir_mul_imm(build, x, y, true);
+}
+
+static inline nir_ssa_def *
 nir_fadd_imm(nir_builder *build, nir_ssa_def *x, double y)
 {
    return nir_fadd(build, x, nir_imm_floatN_t(build, y, x->bit_size));