[llvm] [RISCV] Add tied source operand to Zvqdotq MC instructions. (PR #155286)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/155286

This is consistent with what we do for integer and FP multiply accumulate instructions.

We need new classes because normal multiply accumulate have the operands in a different order.

>From 76b297e65b4bd4b78dc33a053b5bce2c8617e2fd Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Mon, 25 Aug 2025 13:11:43 -0700
Subject: [PATCH] [RISCV] Add tied source operand to Zvqdotq MC instructions.

This is consistent with what we do for integer and FP multiply
accumulate instructions.
---
 .../lib/Target/RISCV/RISCVInstrInfoZvqdotq.td | 45 ++++++++++++++++---
 1 file changed, 38 insertions(+), 7 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoZvqdotq.td b/llvm/lib/Target/RISCV/RISCVInstrInfoZvqdotq.td
index 27959eaccd904..64fd50839f01c 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoZvqdotq.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoZvqdotq.td
@@ -17,16 +17,39 @@
 // Instructions
 //===----------------------------------------------------------------------===//
 
+class VQDOTVV<bits<6> funct6, RISCVVFormat opv, string opcodestr>
+    : RVInstVV<funct6, opv, (outs VR:$vd_wb),
+                (ins VR:$vd, VR:$vs2, VR:$vs1, VMaskOp:$vm),
+                opcodestr, "$vd, $vs2, $vs1$vm"> {
+  let mayLoad = 0;
+  let mayStore = 0;
+  let hasSideEffects = 0;
+  let Constraints = "$vd = $vd_wb";
+}
+
+class VQDOTVX<bits<6> funct6, RISCVVFormat opv, string opcodestr>
+    : RVInstVX<funct6, opv, (outs VR:$vd_wb),
+                (ins VR:$vd, VR:$vs2, GPR:$rs1, VMaskOp:$vm),
+                opcodestr, "$vd, $vs2, $rs1$vm"> {
+  let mayLoad = 0;
+  let mayStore = 0;
+  let hasSideEffects = 0;
+  let Constraints = "$vd = $vd_wb";
+}
+
 let Predicates = [HasStdExtZvqdotq] in {
-  def VQDOT_VV   : VALUVV<0b101100, OPMVV, "vqdot.vv">;
-  def VQDOT_VX   : VALUVX<0b101100, OPMVX, "vqdot.vx">;
-  def VQDOTU_VV  : VALUVV<0b101000, OPMVV, "vqdotu.vv">;
-  def VQDOTU_VX  : VALUVX<0b101000, OPMVX, "vqdotu.vx">;
-  def VQDOTSU_VV : VALUVV<0b101010, OPMVV, "vqdotsu.vv">;
-  def VQDOTSU_VX : VALUVX<0b101010, OPMVX, "vqdotsu.vx">;
-  def VQDOTUS_VX : VALUVX<0b101110, OPMVX, "vqdotus.vx">;
+  def VQDOT_VV   : VQDOTVV<0b101100, OPMVV, "vqdot.vv">;
+  def VQDOT_VX   : VQDOTVX<0b101100, OPMVX, "vqdot.vx">;
+  def VQDOTU_VV  : VQDOTVV<0b101000, OPMVV, "vqdotu.vv">;
+  def VQDOTU_VX  : VQDOTVX<0b101000, OPMVX, "vqdotu.vx">;
+  def VQDOTSU_VV : VQDOTVV<0b101010, OPMVV, "vqdotsu.vv">;
+  def VQDOTSU_VX : VQDOTVX<0b101010, OPMVX, "vqdotsu.vx">;
+  def VQDOTUS_VX : VQDOTVX<0b101110, OPMVX, "vqdotus.vx">;
 } // Predicates = [HasStdExtZvqdotq]
 
+//===----------------------------------------------------------------------===//
+// Helpers to define the VL patterns.
+//===----------------------------------------------------------------------===//
 
 let HasPassthruOp = true, HasMaskOp = true in {
   def riscv_vqdot_vl : RVSDNode<"VQDOT_VL", SDT_RISCVIntBinOp_VL>;
@@ -34,6 +57,10 @@ let HasPassthruOp = true, HasMaskOp = true in {
   def riscv_vqdotsu_vl : RVSDNode<"VQDOTSU_VL", SDT_RISCVIntBinOp_VL>;
 } // let HasPassthruOp = true, HasMaskOp = true
 
+//===----------------------------------------------------------------------===//
+// Pseudo Instructions for CodeGen
+//===----------------------------------------------------------------------===//
+
 multiclass VPseudoVQDOT_VV_VX {
   foreach m = MxSet<32>.m in {
     defm "" : VPseudoBinaryV_VV<m>,
@@ -54,6 +81,10 @@ let Predicates = [HasStdExtZvqdotq], mayLoad = 0, mayStore = 0,
   defm PseudoVQDOTSU : VPseudoVQDOT_VV_VX;
 }
 
+//===----------------------------------------------------------------------===//
+// Patterns.
+//===----------------------------------------------------------------------===//
+
 defvar AllE32Vectors = [VI32MF2, VI32M1, VI32M2, VI32M4, VI32M8];
 defm : VPatBinaryVL_VV_VX<riscv_vqdot_vl, "PseudoVQDOT", AllE32Vectors>;
 defm : VPatBinaryVL_VV_VX<riscv_vqdotu_vl, "PseudoVQDOTU", AllE32Vectors>;