[llvm] [LoongArch] Pre-commit test for loop term fold pass & vector sext, zext (PR #131742)

[Lu Weining via llvm-commits]

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@@ -0,0 +1,113 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc --mtriple=loongarch64 --mattr=+d < %s | FileCheck %s
+
+;; Whether Loop Term Fold Pass is enabled or not, this test only contains 2 add instructions.
+define void @const_tripcount_le_1024(ptr %a, ptr %b) {
+; CHECK-LABEL: const_tripcount_le_1024:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    move $a2, $zero
+; CHECK-NEXT:    ori $a3, $zero, 2048
+; CHECK-NEXT:    .p2align 4, , 16
+; CHECK-NEXT:  .LBB0_1: # %for.body
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    ldx.h $a4, $a1, $a2
+; CHECK-NEXT:    st.w $a4, $a0, 0
+; CHECK-NEXT:    addi.d $a2, $a2, 2
+; CHECK-NEXT:    addi.d $a0, $a0, 4
+; CHECK-NEXT:    bne $a2, $a3, .LBB0_1
+; CHECK-NEXT:  # %bb.2: # %for.cond.cleanup
+; CHECK-NEXT:    ret
+entry:
+  br label %for.body
+
+for.cond.cleanup:
+  ret void
+
+for.body:
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %arrayidx = getelementptr inbounds nuw i16, ptr %b, i64 %indvars.iv
+  %0 = load i16, ptr %arrayidx
+  %conv = sext i16 %0 to i32
+  %arrayidx2 = getelementptr inbounds nuw i32, ptr %a, i64 %indvars.iv
+  store i32 %conv, ptr %arrayidx2
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv.next, 1024
+  br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
+}
+
+
+;; After Loop Term Fold Pass enabled, this test only contains 2 add instructions.
----------------
SixWeining wrote:

```suggestion
;; TODO: After the Loop Term Fold Pass is enabled by PR130737, this particular test yields merely two add instructions, one fewer than previously.
```

https://github.com/llvm/llvm-project/pull/131742