[llvm] [Mips] When emit instruction, ignore JUMP_TABLE_DEBUG_INFO (PR #139830)

[via llvm-commits]

https://github.com/yingopq updated https://github.com/llvm/llvm-project/pull/139830

>From e021e15783237df5065ecd500b80e5f147d73685 Mon Sep 17 00:00:00 2001
From: Ying Huang <ying.huang at oss.cipunited.com>
Date: Tue, 13 May 2025 23:04:45 -0400
Subject: [PATCH] [Mips] When emit instruction, ignore JUMP_TABLE_DEBUG_INFO

When -triple is windows, SelectionDAGLegalize process Legalizing
br_jt, would generate ISD::JUMP_TABLE_DEBUG_INFO.
Then Mips process emitInstruction, would think JUMP_TABLE_DEBUG_INFO
is a pseudo instruction and generate an error `Pseudo opcode found
in emitInstruction()`.
This instruction `TargetOpcode::JUMP_TABLE_DEBUG_INFO` is only used
to note jump table debug info, so we can ignore it when Mips emit
instruction.

Fix #134916.
---
 llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp |  6 +-
 llvm/test/CodeGen/Mips/jumptable_labels.ll   | 60 +++++++++++++++++++-
 2 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
index 9d07512b7d8a6..d13c88b952ab4 100644
--- a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
+++ b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
@@ -694,8 +694,10 @@ bool MipsDelaySlotFiller::searchRange(MachineBasicBlock &MBB, IterTy Begin,
     IterTy CurrI = I;
     ++I;
     LLVM_DEBUG(dbgs() << DEBUG_TYPE ": checking instruction: "; CurrI->dump());
-    // skip debug value
-    if (CurrI->isDebugInstr()) {
+    // Skip debug value.
+    // Instruction TargetOpcode::JUMP_TABLE_DEBUG_INFO is only used to note
+    // jump table debug info, we did not need to emit it.
+    if (CurrI->isDebugInstr() || CurrI->isJumpTableDebugInfo()) {
       LLVM_DEBUG(dbgs() << DEBUG_TYPE ": ignoring debug instruction: ";
                  CurrI->dump());
       continue;
diff --git a/llvm/test/CodeGen/Mips/jumptable_labels.ll b/llvm/test/CodeGen/Mips/jumptable_labels.ll
index 075b57e08d35e..00b801bd5ddbc 100644
--- a/llvm/test/CodeGen/Mips/jumptable_labels.ll
+++ b/llvm/test/CodeGen/Mips/jumptable_labels.ll
@@ -1,6 +1,7 @@
 ; RUN: llc -mtriple=mips-elf < %s | FileCheck %s -check-prefix=O32
 ; RUN: llc -mtriple=mips64-elf -target-abi=n32 < %s | FileCheck %s -check-prefix=N32
 ; RUN: llc -mtriple=mips64-elf < %s | FileCheck %s -check-prefix=N64
+; RUN: llc -mtriple=mipsel-windows-gnu < %s | FileCheck %s -check-prefix=MIPSEL
 
 ; We only use the '$' prefix on O32. The others use the ELF convention.
 ; O32: $JTI0_0
@@ -12,6 +13,63 @@
 ; N32: .LBB0_2:
 ; N64: .LBB0_2:
 
+; MIPSEL-LABEL: _Z3foo:
+; MIPSEL:       # %bb.0: # %entry
+; MIPSEL-NEXT:    addiu $sp, $sp, -16
+; MIPSEL-NEXT:    sltiu	$1, $4, 7
+; MIPSEL-NEXT:    beqz $1, .LBB0_6
+; MIPSEL-NEXT:    sw $4, 4($sp)
+; MIPSEL-NEXT:  # %bb.1: # %entry
+; MIPSEL-NEXT:    sll $1, $4, 2
+; MIPSEL-NEXT:    lui $2, %hi($JTI0_0)
+; MIPSEL-NEXT:    addu $1, $1, $2
+; MIPSEL-NEXT:    lw $1, %lo($JTI0_0)($1)
+; MIPSEL-NEXT:    jr $1
+; MIPSEL-NEXT:    nop
+; MIPSEL-NEXT:  .LBB0_2: # %sw.bb
+; MIPSEL-NEXT:    lui $1, %hi($.str)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_3: # %sw.bb4
+; MIPSEL-NEXT:    lui $1, %hi($.str.4)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.4)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_4: # %sw.bb2
+; MIPSEL-NEXT:    lui $1, %hi($.str.2)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.2)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_5: # %sw.bb3
+; MIPSEL-NEXT:    lui $1, %hi($.str.3)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.3)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_6: # %sw.epilog
+; MIPSEL-NEXT:    lui $1, %hi($.str.7)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.7)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_7: # %sw.bb1
+; MIPSEL-NEXT:    lui $1, %hi($.str.1)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.1)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_8: # %sw.bb5
+; MIPSEL-NEXT:    lui $1, %hi($.str.5)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.5)
+; MIPSEL-NEXT:    j .LBB0_10
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_9: # %sw.bb6
+; MIPSEL-NEXT:    lui $1, %hi($.str.6)
+; MIPSEL-NEXT:    addiu	$1, $1, %lo($.str.6)
+; MIPSEL-NEXT:    sw $1, 8($sp)
+; MIPSEL-NEXT:  .LBB0_10: # %return
+; MIPSEL-NEXT:    lw $2, 8($sp)
+; MIPSEL-NEXT:    jr $ra
+; MIPSEL-NEXT:    addiu	$sp, $sp, 16
+
 @.str = private unnamed_addr constant [2 x i8] c"A\00", align 1
 @.str.1 = private unnamed_addr constant [2 x i8] c"B\00", align 1
 @.str.2 = private unnamed_addr constant [2 x i8] c"C\00", align 1
@@ -21,7 +79,7 @@
 @.str.6 = private unnamed_addr constant [2 x i8] c"G\00", align 1
 @.str.7 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
 
-define ptr @_Z3fooi(i32 signext %Letter) {
+define ptr @_Z3foo(i32 signext %Letter) {
 entry:
   %retval = alloca ptr, align 8
   %Letter.addr = alloca i32, align 4