Skip to content

Apply the AdjustICmpImmAndPred optimization when it results in a one-instruction immediate materialization over a two-instruction materialization. #83218

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 12, 2024

Conversation

resistor
Copy link
Collaborator

@llvmbot
Copy link
Member

llvmbot commented Feb 28, 2024

@llvm/pr-subscribers-llvm-globalisel

@llvm/pr-subscribers-backend-aarch64

Author: Owen Anderson (resistor)

Changes

#76460


Full diff: https://github.com/llvm/llvm-project/pull/83218.diff

2 Files Affected:

  • (modified) llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp (+8-4)
  • (added) llvm/test/CodeGen/AArch64/GlobalISel/icmp-cst.ll (+185)
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp b/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
index 9bc5815ae05371..96c97cb4706d55 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
@@ -588,7 +588,8 @@ tryAdjustICmpImmAndPred(Register RHS, CmpInst::Predicate P,
   auto ValAndVReg = getIConstantVRegValWithLookThrough(RHS, MRI);
   if (!ValAndVReg)
     return std::nullopt;
-  uint64_t C = ValAndVReg->Value.getZExtValue();
+  uint64_t OriginalC = ValAndVReg->Value.getZExtValue();
+  uint64_t C = OriginalC;
   if (isLegalArithImmed(C))
     return std::nullopt;
 
@@ -658,9 +659,12 @@ tryAdjustICmpImmAndPred(Register RHS, CmpInst::Predicate P,
   // predicate if it is.
   if (Size == 32)
     C = static_cast<uint32_t>(C);
-  if (!isLegalArithImmed(C))
-    return std::nullopt;
-  return {{C, P}};
+  if (isLegalArithImmed(C))
+    return {{C, P}};
+  if (AArch64_AM::isLogicalImmediate(C, Size) &&
+      !AArch64_AM::isLogicalImmediate(OriginalC, Size))
+    return {{C, P}};
+  return std::nullopt;
 }
 
 /// Determine whether or not it is possible to update the RHS and predicate of
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/icmp-cst.ll b/llvm/test/CodeGen/AArch64/GlobalISel/icmp-cst.ll
new file mode 100644
index 00000000000000..e6b27943372a83
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/icmp-cst.ll
@@ -0,0 +1,185 @@
+; RUN: llc -mtriple=aarch64-linux-gnu -global-isel=1 < %s | FileCheck %s
+
+; CHECK-NOT: movk
+
+define dso_local noundef i1 @ule_11111111(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 286331154
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_22222222(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 572662307
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_33333333(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 858993460
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_44444444(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 1145324613
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_55555555(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 1431655766
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_66666666(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 1717986919
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_77777777(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, 2004318072
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_88888888(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, -2004318071
+  ret i1 %2
+}
+
+define dso_local noundef i1 @ule_99999999(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, -1717986918
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_11111111(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 286331152
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_22222222(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 572662305
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_33333333(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 858993458
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_44444444(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 1145324611
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_55555555(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 1431655764
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_66666666(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 1717986917
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_77777777(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, 2004318070
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_88888888(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, -2004318073
+  ret i1 %2
+}
+
+define dso_local noundef i1 @uge_99999999(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, -1717986920
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_11111111(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 286331154
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_22222222(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 572662307
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_33333333(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 858993460
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_44444444(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 1145324613
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_55555555(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 1431655766
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_66666666(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 1717986919
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_77777777(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp slt i32 %0, 2004318072
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_88888888(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, -2004318071
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sle_99999999(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ult i32 %0, -1717986918
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_11111111(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 286331152
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_22222222(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 572662305
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_33333333(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 858993458
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_44444444(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 1145324611
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_55555555(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 1431655764
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_66666666(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 1717986917
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_77777777(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp sgt i32 %0, 2004318070
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_88888888(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, -2004318073
+  ret i1 %2
+}
+
+define dso_local noundef i1 @sge_99999999(i32 noundef %0) local_unnamed_addr #0 {
+  %2 = icmp ugt i32 %0, -1717986920
+  ret i1 %2
+}
+
+attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+outline-atomics,+v8a,-fmv" }
\ No newline at end of file

if (isLegalArithImmed(C))
return {{C, P}};
if (AArch64_AM::isLogicalImmediate(C, Size) &&
!AArch64_AM::isLogicalImmediate(OriginalC, Size))
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It would be a bit more code, but could this all use AArch64_IMM::expandMOVImm(Imm, BitSize, Insn); Insn.size() == 1? I believe that is what this is trying to achieve, and it would be more general to capture all the different ways for the immediate to be a single instruction.

Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

ping on this comment? @resistor

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I've long since lost the context on this one, but feel free to adopt it if you want.

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done

@davemgreen
Copy link
Collaborator

It would be good if the title had [AArch64][GlobalISel] too, to keep in consistent with all the other commits. The title might be a bit long too for a standard git commit. Some of it might fit better as the message.

Copy link
Collaborator

@davemgreen davemgreen left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for the update. LGTM if @ornata doesn't disagree.

a one-instruction immediate materialization over a two-instruction
materialization.

llvm#76460
@resistor resistor merged commit 46c05df into llvm:main Jun 12, 2024
1 of 2 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Development

Successfully merging this pull request may close these issues.

5 participants