kraid: Add alloc_vec utility

Signed-off-by: Lorenzo Rossi <lorenzo.rossi@collabora.com>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/42189>

src/panfrost/compiler/kraid/builder.rs

@@ -36,6 +36,8 @@ pub trait Builder {
 pub trait SSABuilder: Builder {
     fn alloc_ssa(&mut self, bits: u8) -> SSAValue;
 
+    fn alloc_vec(&mut self, comps: u8) -> SSARef;
+
     fn copy_i8(&mut self, src: Src) -> SSAValue {
         let def = self.alloc_ssa(8);
         self.copy_i8_to(def.into(), src);
@@ -164,4 +166,8 @@ impl SSABuilder for SSAInstrBuilder<'_> {
     fn alloc_ssa(&mut self, bits: u8) -> SSAValue {
         self.alloc.alloc(bits)
     }
+
+    fn alloc_vec(&mut self, comps: u8) -> SSARef {
+        self.alloc.alloc_vec(comps)
+    }
 }

src/panfrost/compiler/kraid/ssa_value.rs

@@ -126,6 +126,19 @@ impl SSARef {
         self.as_mut_slice().iter_mut()
     }
 
+    pub fn from_iter(it: impl ExactSizeIterator<Item = SSAValue>) -> Self {
+        let len = it.len();
+
+        let inner = if len <= SSARefInnerShort::MAX_LEN {
+            SSARefInner::Short(it.map(|x| x.packed).collect())
+        } else {
+            assert!(len <= SSARefInnerLong::MAX_LEN);
+            SSARefInner::Long(Box::new(it.map(|x| x.packed).collect()))
+        };
+
+        Self { v: inner }
+    }
+
     #[cold]
     #[inline]
     fn cold() {}
@@ -271,6 +284,10 @@ impl SSAValueAllocator {
         self.count += 1;
         SSAValue::new(idx, bits)
     }
+
+    pub fn alloc_vec(&mut self, comps: u8) -> SSARef {
+        SSARef::from_iter((0..comps).map(|_| self.alloc(32)))
+    }
 }
 
 #[cfg(test)]