[RISCV] Precommit test for tail duplication

Author: wangpc-pp

llvm/test/CodeGen/RISCV/riscv-tail-dup-size.ll

@@ -0,0 +1,76 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv64 -mattr=+m -O2 < %s | FileCheck %s --check-prefix=CHECK-O2
+; RUN: llc -mtriple=riscv64 -mattr=+m -O3 < %s | FileCheck %s --check-prefix=CHECK-O3
+
+; RUN: llc -mtriple=riscv64 -mattr=+m -tail-dup-size=4 < %s | FileCheck %s --check-prefix=CHECK-O2
+; RUN: llc -mtriple=riscv64 -mattr=+m -tail-dup-placement-threshold=4 < %s | FileCheck %s --check-prefix=CHECK-O2
+; RUN: llc -mtriple=riscv64 -mattr=+m -tail-dup-placement-threshold=4 < %s | FileCheck %s --check-prefix=CHECK-O3
+
+@a = external dso_local local_unnamed_addr global i32
+@b = external dso_local local_unnamed_addr global i32
+@c = external dso_local local_unnamed_addr global i32
+
+declare i32 @foo(i32)
+
+define dso_local i32 @test(i32 %n) {
+; CHECK-O2-LABEL: test:
+; CHECK-O2:       # %bb.0: # %entry
+; CHECK-O2-NEXT:    sext.w a1, a0
+; CHECK-O2-NEXT:    blez a1, .LBB0_2
+; CHECK-O2-NEXT:  # %bb.1: # %if.then
+; CHECK-O2-NEXT:    lui a1, %hi(a)
+; CHECK-O2-NEXT:    lw a1, %lo(a)(a1)
+; CHECK-O2-NEXT:    mul a0, a1, a0
+; CHECK-O2-NEXT:    j .LBB0_3
+; CHECK-O2-NEXT:  .LBB0_2: # %if.else
+; CHECK-O2-NEXT:    lui a1, %hi(b)
+; CHECK-O2-NEXT:    lw a1, %lo(b)(a1)
+; CHECK-O2-NEXT:    divw a0, a1, a0
+; CHECK-O2-NEXT:  .LBB0_3: # %if.end
+; CHECK-O2-NEXT:    lui a1, %hi(c)
+; CHECK-O2-NEXT:    lw a1, %lo(c)(a1)
+; CHECK-O2-NEXT:    addi a0, a0, -1
+; CHECK-O2-NEXT:    mulw a0, a0, a1
+; CHECK-O2-NEXT:    tail foo
+;
+; CHECK-O3-LABEL: test:
+; CHECK-O3:       # %bb.0: # %entry
+; CHECK-O3-NEXT:    sext.w a1, a0
+; CHECK-O3-NEXT:    blez a1, .LBB0_2
+; CHECK-O3-NEXT:  # %bb.1: # %if.then
+; CHECK-O3-NEXT:    lui a1, %hi(a)
+; CHECK-O3-NEXT:    lw a1, %lo(a)(a1)
+; CHECK-O3-NEXT:    mul a0, a1, a0
+; CHECK-O3-NEXT:    j .LBB0_3
+; CHECK-O3-NEXT:  .LBB0_2: # %if.else
+; CHECK-O3-NEXT:    lui a1, %hi(b)
+; CHECK-O3-NEXT:    lw a1, %lo(b)(a1)
+; CHECK-O3-NEXT:    divw a0, a1, a0
+; CHECK-O3-NEXT:  .LBB0_3: # %if.end
+; CHECK-O3-NEXT:    lui a1, %hi(c)
+; CHECK-O3-NEXT:    lw a1, %lo(c)(a1)
+; CHECK-O3-NEXT:    addi a0, a0, -1
+; CHECK-O3-NEXT:    mulw a0, a0, a1
+; CHECK-O3-NEXT:    tail foo
+entry:
+  %cmp = icmp sgt i32 %n, 0
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:
+  %va = load i32, ptr @a
+  %mul = mul nsw i32 %va, %n
+  br label %if.end
+
+if.else:
+  %vb = load i32, ptr @b
+  %div = sdiv i32 %vb, %n
+  br label %if.end
+
+if.end:
+  %phi = phi i32 [ %mul, %if.then ], [ %div, %if.else ]
+  %vc = load i32, ptr @c
+  %add = add nsw i32 %phi, -1
+  %arg = mul i32 %add, %vc
+  %ret = tail call i32 @foo(i32 %arg)
+  ret i32 %ret
+}