From a53cb9f55ccb4560cd1c7cdccb7d4a5ffe1a6b09 Mon Sep 17 00:00:00 2001
From: Faith Ekstrand <faith.ekstrand@collabora.com>
Date: Thu, 11 Jun 2026 16:08:36 -0400
Subject: [PATCH] kraid/v9: Fold swizzles and modifiers on imm1w sources

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/42200>
---
 src/panfrost/compiler/kraid/encode_v9.rs | 30 +++++++++++++++++-------
 src/panfrost/compiler/kraid/ir.rs        | 18 ++++++++++++++
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/src/panfrost/compiler/kraid/encode_v9.rs b/src/panfrost/compiler/kraid/encode_v9.rs
index d1a6a27b421..38166f6607e 100644
--- a/src/panfrost/compiler/kraid/encode_v9.rs
+++ b/src/panfrost/compiler/kraid/encode_v9.rs
@@ -167,6 +167,20 @@ fn ptr_eq<T>(a: &T, b: &T) -> bool {
     (a as *const T) == (b as *const T)
 }
 
+fn typed_src_as_imm1w(src: &Src, src_type: DataType) -> Option<u32> {
+    let SrcRef::Imm32(imm) = &src.src_ref else {
+        return None;
+    };
+
+    let imm = src.swizzle.fold_u32(imm.get()).unwrap();
+    let imm = src.src_mod.fold_u32(src_type, imm).unwrap();
+    Some(imm)
+}
+
+fn op_src_as_imm1w(op: &impl Opcode, src: &Src) -> Option<u32> {
+    typed_src_as_imm1w(src, op.src_type(src))
+}
+
 fn encode_src_ref(src: &SrcRef, last_use: bool) -> u8 {
     match src {
         SrcRef::Zero => 0b1100_0000,
@@ -601,12 +615,12 @@ impl V9Instr for OpFAdd {
     }
 
     fn encode(&self, e: V9Encoder) -> EncodedInstr {
-        if let SrcRef::Imm32(imm) = &self.srcs[1].src_ref {
+        if let Some(imm1w) = op_src_as_imm1w(self, &self.srcs[1]) {
             e.encode(FaddImm {
                 variant: self.dst_type.try_into().unwrap(),
                 dst: op_encode_dst(self, &self.dst),
                 src0: op_encode_src(self, &self.srcs[0]),
-                imm1w: (*imm).into(),
+                imm1w,
             })
         } else {
             e.encode(Fadd {
@@ -661,12 +675,12 @@ impl V9Instr for OpIAdd {
     }
 
     fn encode(&self, e: V9Encoder) -> EncodedInstr {
-        if let SrcRef::Imm32(imm) = &self.srcs[1].src_ref {
+        if let Some(imm1w) = op_src_as_imm1w(self, &self.srcs[1]) {
             e.encode(IaddImm {
                 variant: self.dst_type.try_into().unwrap(),
                 dst: op_encode_dst(self, &self.dst),
                 src0: op_encode_src(self, &self.srcs[0]),
-                imm1w: (*imm).into(),
+                imm1w,
             })
         } else {
             e.encode(Iadd {
@@ -833,11 +847,11 @@ impl V9Instr for OpMov {
     }
 
     fn encode(&self, e: V9Encoder) -> EncodedInstr {
-        if let SrcRef::Imm32(imm) = &self.src.src_ref {
+        if let Some(imm1w) = op_src_as_imm1w(self, &self.src) {
             e.encode(MovImm {
                 variant: self.dst_type.try_into().unwrap(),
                 dst: op_encode_dst(self, &self.dst),
-                imm1w: (*imm).into(),
+                imm1w,
             })
         } else {
             e.encode(Mov {
@@ -862,13 +876,13 @@ impl V9Instr for OpNop {
 macro_rules! encode_lop {
     ($e:expr, $op:expr, $Instr:ident) => {
         paste! {
-            if let SrcRef::Imm32(imm) = &$op.src2.src_ref {
+            if let Some(imm1w) = op_src_as_imm1w($op, &$op.src2) {
                 assert!(!$op.not_result);
                 $e.encode(v9::[<$Instr Imm>] {
                     variant: $op.dst_type.try_into().unwrap(),
                     dst: op_encode_dst($op, &$op.dst),
                     src0: op_encode_src($op, &$op.src0),
-                    imm1w: (*imm).into(),
+                    imm1w,
                 })
             } else {
                 $e.encode(v9::$Instr {
diff --git a/src/panfrost/compiler/kraid/ir.rs b/src/panfrost/compiler/kraid/ir.rs
index c6b3d129532..f0c197c8d16 100644
--- a/src/panfrost/compiler/kraid/ir.rs
+++ b/src/panfrost/compiler/kraid/ir.rs
@@ -269,6 +269,14 @@ impl fmt::Display for SrcMod {
     }
 }
 
+fn float_sign_bits(data_type: DataType) -> Option<u32> {
+    match data_type {
+        DataType::F16 | DataType::V2F16 => Some(0x80008000),
+        DataType::F32 => Some(0x80000000),
+        _ => None,
+    }
+}
+
 impl SrcMod {
     pub fn bnot(self) -> SrcMod {
         use SrcMod::*;
@@ -310,6 +318,16 @@ impl SrcMod {
             BNot => self.bnot(),
         }
     }
+
+    pub fn fold_u32(self, data_type: DataType, u: u32) -> Option<u32> {
+        match self {
+            SrcMod::None => Some(u),
+            SrcMod::FAbs => Some(u & !float_sign_bits(data_type)?),
+            SrcMod::FNeg => Some(u ^ float_sign_bits(data_type)?),
+            SrcMod::FNegAbs => Some(u | float_sign_bits(data_type)?),
+            SrcMod::BNot => Some(!u),
+        }
+    }
 }
 
 #[derive(Clone)]