From 94293ccfba219e6f49a3216f3f45268f76b032e6 Mon Sep 17 00:00:00 2001
From: Lucas <lucas.tnagel@gmail.com>
Date: Wed, 15 Jan 2025 15:34:32 -0300
Subject: [PATCH] Expand mulh for 32-bit

---
 llvm/lib/Target/SBF/SBFISelLowering.cpp |  5 ++
 llvm/test/CodeGen/SBF/mulh.ll           | 62 +++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 llvm/test/CodeGen/SBF/mulh.ll

diff --git a/llvm/lib/Target/SBF/SBFISelLowering.cpp b/llvm/lib/Target/SBF/SBFISelLowering.cpp
index f0b8e2cf31215c..4bf6f943478615 100644
--- a/llvm/lib/Target/SBF/SBFISelLowering.cpp
+++ b/llvm/lib/Target/SBF/SBFISelLowering.cpp
@@ -124,6 +124,11 @@ SBFTargetLowering::SBFTargetLowering(const TargetMachine &TM,
     setOperationAction(ISD::SELECT_CC, VT, Custom);
   }
 
+  if (STI.getHasPqrClass() && STI.getHasAlu32()) {
+    setOperationAction(ISD::MULHU, MVT::i32, Expand);
+    setOperationAction(ISD::MULHS, MVT::i32, Expand);
+  }
+
   if (STI.getHasAlu32()) {
     setOperationAction(ISD::BSWAP, MVT::i32, Promote);
     setOperationAction(ISD::BR_CC, MVT::i32, Custom);
diff --git a/llvm/test/CodeGen/SBF/mulh.ll b/llvm/test/CodeGen/SBF/mulh.ll
new file mode 100644
index 00000000000000..23415859df2156
--- /dev/null
+++ b/llvm/test/CodeGen/SBF/mulh.ll
@@ -0,0 +1,62 @@
+; RUN: llc -O2 -march=sbf -mcpu=v2 < %s | FileCheck %s
+
+define dso_local i32 @test_32_unsigned(i32 noundef %a, i32 noundef %b) {
+entry:
+; CHECK-LABEL: test_32_unsigned
+  %conv = zext i32 %a to i64
+  %conv1 = zext i32 %b to i64
+  %mul = mul nuw i64 %conv1, %conv
+  %shr = lshr i64 %mul, 32
+  %conv2 = trunc i64 %shr to i32
+  ret i32 %conv2
+
+; CHECK: mov64 w0, w2
+; CHECK: lmul64 r0, r1
+; CHECK: rsh64 r0, 32
+; CHECK: and32 w0, -1
+}
+
+define dso_local i32 @test_32_signed(i32 noundef %a, i32 noundef %b) {
+entry:
+
+; CHECK-LABEL: test_32_signed
+  %conv = sext i32 %a to i64
+  %conv1 = sext i32 %b to i64
+  %mul = mul nsw i64 %conv1, %conv
+  %shr = lshr i64 %mul, 32
+  %conv2 = trunc i64 %shr to i32
+  ret i32 %conv2
+
+; CHECK: mov32 r1, w1
+; CHECK: mov32 r0, w2
+; CHECK: lmul64 r0, r1
+; CHECK: rsh64 r0, 32
+; CHECK: and32 w0, -1
+
+}
+
+define dso_local i64 @test_64_unsigned(i64 noundef %a, i64 noundef %b)  {
+entry:
+; CHECK-LABEL: test_64_unsigned
+  %conv = zext i64 %a to i128
+  %conv1 = zext i64 %b to i128
+  %mul = mul nuw i128 %conv1, %conv
+  %shr = lshr i128 %mul, 64
+  %conv2 = trunc i128 %shr to i64
+  ret i64 %conv2
+
+; CHECK: uhmul64 r0, r1
+}
+
+define dso_local i64 @test_64_signed(i64 noundef %a, i64 noundef %b) {
+entry:
+; CHECK-LABEL: test_64_signed
+  %conv = sext i64 %a to i128
+  %conv1 = sext i64 %b to i128
+  %mul = mul nsw i128 %conv1, %conv
+  %shr = lshr i128 %mul, 64
+  %conv2 = trunc i128 %shr to i64
+  ret i64 %conv2
+
+; CHECK: shmul64 r0, r1
+}
\ No newline at end of file