[RISCV][test] Precommit a test of CSE within an unroll loop

Reviewed By: asb, frasercrmck

Differential Revision: https://reviews.llvm.org/D118218

llvm/test/CodeGen/RISCV/unroll-loop-cse.ll

@@ -0,0 +1,92 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=riscv64 -verify-machineinstrs < %s | FileCheck %s
+
+@x = global [6 x i32] [i32 0, i32 1, i32 2, i32 3, i32 4, i32 5], align 4
+@check = global [6 x i32] [i32 0, i32 1, i32 2, i32 3, i32 4, i32 5], align 4
+
+; This test case checks whether the base address of an array is repeatedly
+; rematerialised within a unrolled loop.
+define signext i32 @unroll_loop_cse() {
+; CHECK-LABEL: unroll_loop_cse:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lui a1, %hi(x)
+; CHECK-NEXT:    lw a3, %lo(x)(a1)
+; CHECK-NEXT:    lui a2, %hi(check)
+; CHECK-NEXT:    lw a4, %lo(check)(a2)
+; CHECK-NEXT:    li a0, 1
+; CHECK-NEXT:    bne a3, a4, .LBB0_6
+; CHECK-NEXT:  # %bb.1:
+; CHECK-NEXT:    addi a1, a1, %lo(x)
+; CHECK-NEXT:    lw a1, 4(a1)
+; CHECK-NEXT:    addi a2, a2, %lo(check)
+; CHECK-NEXT:    lw a2, 4(a2)
+; CHECK-NEXT:    bne a1, a2, .LBB0_6
+; CHECK-NEXT:  # %bb.2:
+; CHECK-NEXT:    lui a1, %hi(x)
+; CHECK-NEXT:    addi a1, a1, %lo(x)
+; CHECK-NEXT:    lw a3, 8(a1)
+; CHECK-NEXT:    lui a2, %hi(check)
+; CHECK-NEXT:    addi a2, a2, %lo(check)
+; CHECK-NEXT:    lw a4, 8(a2)
+; CHECK-NEXT:    bne a3, a4, .LBB0_6
+; CHECK-NEXT:  # %bb.3:
+; CHECK-NEXT:    lw a1, 12(a1)
+; CHECK-NEXT:    lw a2, 12(a2)
+; CHECK-NEXT:    bne a1, a2, .LBB0_6
+; CHECK-NEXT:  # %bb.4:
+; CHECK-NEXT:    lui a1, %hi(x)
+; CHECK-NEXT:    addi a1, a1, %lo(x)
+; CHECK-NEXT:    lw a3, 16(a1)
+; CHECK-NEXT:    lui a2, %hi(check)
+; CHECK-NEXT:    addi a2, a2, %lo(check)
+; CHECK-NEXT:    lw a4, 16(a2)
+; CHECK-NEXT:    bne a3, a4, .LBB0_6
+; CHECK-NEXT:  # %bb.5:
+; CHECK-NEXT:    lw a0, 20(a1)
+; CHECK-NEXT:    lw a1, 20(a2)
+; CHECK-NEXT:    xor a0, a0, a1
+; CHECK-NEXT:    snez a0, a0
+; CHECK-NEXT:  .LBB0_6:
+; CHECK-NEXT:    ret
+  %1 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 0), align 4
+  %2 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 0), align 4
+  %3 = icmp eq i32 %1, %2
+  br i1 %3, label %4, label %25
+
+4:
+  %5 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 1), align 4
+  %6 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 1), align 4
+  %7 = icmp eq i32 %5, %6
+  br i1 %7, label %8, label %25
+
+8:
+  %9 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 2), align 4
+  %10 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 2), align 4
+  %11 = icmp eq i32 %9, %10
+  br i1 %11, label %12, label %25
+
+12:
+  %13 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 3), align 4
+  %14 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 3), align 4
+  %15 = icmp eq i32 %13, %14
+  br i1 %15, label %16, label %25
+
+16:
+  %17 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 4), align 4
+  %18 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 4), align 4
+  %19 = icmp eq i32 %17, %18
+  br i1 %19, label %20, label %25
+
+20:
+  %21 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @x, i64 0, i64 5), align 4
+  %22 = load i32, i32* getelementptr inbounds ([6 x i32], [6 x i32]* @check, i64 0, i64 5), align 4
+  %23 = icmp ne i32 %21, %22
+  %24 = zext i1 %23 to i32
+  br label %25
+
+25:
+  %26 = phi i32 [ 1, %0 ], [ 1, %4 ], [ 1, %8 ], [ 1, %12 ], [ 1, %16 ], [ %24, %20 ]
+  ret i32 %26
+}
+