From f5800a2aa06fb51a99a873bf7c8d84952480f3ce Mon Sep 17 00:00:00 2001 From: Alex Bradbury Date: Fri, 27 Apr 2018 11:50:30 +0000 Subject: [PATCH] [RISCV] Add remat.ll test case This test case demonstrates suboptimal codegen due to the fact that simple constants aren't recognised as rematerialisable. llvm-svn: 331028 --- llvm/test/CodeGen/RISCV/remat.ll | 209 +++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) create mode 100644 llvm/test/CodeGen/RISCV/remat.ll diff --git a/llvm/test/CodeGen/RISCV/remat.ll b/llvm/test/CodeGen/RISCV/remat.ll new file mode 100644 index 000000000000..a37d6f5afd5b --- /dev/null +++ b/llvm/test/CodeGen/RISCV/remat.ll @@ -0,0 +1,209 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py +; RUN: llc -O1 -mtriple=riscv32 -verify-machineinstrs < %s \ +; RUN: | FileCheck %s -check-prefix=RV32I + +@a = common global i32 0, align 4 +@l = common global i32 0, align 4 +@b = common global i32 0, align 4 +@c = common global i32 0, align 4 +@d = common global i32 0, align 4 +@e = common global i32 0, align 4 +@k = common global i32 0, align 4 +@f = common global i32 0, align 4 +@j = common global i32 0, align 4 +@g = common global i32 0, align 4 +@i = common global i32 0, align 4 +@h = common global i32 0, align 4 + +; This test case benefits from codegen recognising that some values are +; trivially rematerialisable, meaning they are recreated rather than saved to +; the stack and restored. It creates high register pressure to force this +; situation. + +; TODO: it makes no sense to spill %hi(h), %hi(l) or the constant 64 to the +; stack. + +define i32 @test() nounwind { +; RV32I-LABEL: test: +; RV32I: # %bb.0: # %entry +; RV32I-NEXT: addi sp, sp, -64 +; RV32I-NEXT: sw ra, 60(sp) +; RV32I-NEXT: sw s1, 56(sp) +; RV32I-NEXT: sw s2, 52(sp) +; RV32I-NEXT: sw s3, 48(sp) +; RV32I-NEXT: sw s4, 44(sp) +; RV32I-NEXT: sw s5, 40(sp) +; RV32I-NEXT: sw s6, 36(sp) +; RV32I-NEXT: sw s7, 32(sp) +; RV32I-NEXT: sw s8, 28(sp) +; RV32I-NEXT: sw s9, 24(sp) +; RV32I-NEXT: sw s10, 20(sp) +; RV32I-NEXT: sw s11, 16(sp) +; RV32I-NEXT: lui s3, %hi(a) +; RV32I-NEXT: lw a0, %lo(a)(s3) +; RV32I-NEXT: beqz a0, .LBB0_11 +; RV32I-NEXT: # %bb.1: # %for.body.preheader +; RV32I-NEXT: lui a1, %hi(l) +; RV32I-NEXT: sw a1, 12(sp) +; RV32I-NEXT: lui s5, %hi(k) +; RV32I-NEXT: lui s6, %hi(j) +; RV32I-NEXT: lui s7, %hi(i) +; RV32I-NEXT: lui a1, %hi(h) +; RV32I-NEXT: sw a1, 8(sp) +; RV32I-NEXT: lui s9, %hi(g) +; RV32I-NEXT: lui s10, %hi(f) +; RV32I-NEXT: lui s11, %hi(e) +; RV32I-NEXT: lui s8, %hi(d) +; RV32I-NEXT: addi s1, zero, 32 +; RV32I-NEXT: lui s2, %hi(c) +; RV32I-NEXT: lui s4, %hi(b) +; RV32I-NEXT: addi a1, zero, 64 +; RV32I-NEXT: sw a1, 4(sp) +; RV32I-NEXT: .LBB0_2: # %for.body +; RV32I-NEXT: # =>This Inner Loop Header: Depth=1 +; RV32I-NEXT: lw a1, 12(sp) +; RV32I-NEXT: lw a1, %lo(l)(a1) +; RV32I-NEXT: beqz a1, .LBB0_4 +; RV32I-NEXT: # %bb.3: # %if.then +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a4, %lo(e)(s11) +; RV32I-NEXT: lw a3, %lo(d)(s8) +; RV32I-NEXT: lw a2, %lo(c)(s2) +; RV32I-NEXT: lw a1, %lo(b)(s4) +; RV32I-NEXT: mv a5, s1 +; RV32I-NEXT: call foo +; RV32I-NEXT: .LBB0_4: # %if.end +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a0, %lo(k)(s5) +; RV32I-NEXT: beqz a0, .LBB0_6 +; RV32I-NEXT: # %bb.5: # %if.then3 +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a4, %lo(f)(s10) +; RV32I-NEXT: lw a3, %lo(e)(s11) +; RV32I-NEXT: lw a2, %lo(d)(s8) +; RV32I-NEXT: lw a1, %lo(c)(s2) +; RV32I-NEXT: lw a0, %lo(b)(s4) +; RV32I-NEXT: lw a5, 4(sp) +; RV32I-NEXT: call foo +; RV32I-NEXT: .LBB0_6: # %if.end5 +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a0, %lo(j)(s6) +; RV32I-NEXT: beqz a0, .LBB0_8 +; RV32I-NEXT: # %bb.7: # %if.then7 +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a4, %lo(g)(s9) +; RV32I-NEXT: lw a3, %lo(f)(s10) +; RV32I-NEXT: lw a2, %lo(e)(s11) +; RV32I-NEXT: lw a1, %lo(d)(s8) +; RV32I-NEXT: lw a0, %lo(c)(s2) +; RV32I-NEXT: mv a5, s1 +; RV32I-NEXT: call foo +; RV32I-NEXT: .LBB0_8: # %if.end9 +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a0, %lo(i)(s7) +; RV32I-NEXT: beqz a0, .LBB0_10 +; RV32I-NEXT: # %bb.9: # %if.then11 +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a0, 8(sp) +; RV32I-NEXT: lw a4, %lo(h)(a0) +; RV32I-NEXT: lw a3, %lo(g)(s9) +; RV32I-NEXT: lw a2, %lo(f)(s10) +; RV32I-NEXT: lw a1, %lo(e)(s11) +; RV32I-NEXT: lw a0, %lo(d)(s8) +; RV32I-NEXT: mv a5, s1 +; RV32I-NEXT: call foo +; RV32I-NEXT: .LBB0_10: # %for.inc +; RV32I-NEXT: # in Loop: Header=BB0_2 Depth=1 +; RV32I-NEXT: lw a0, %lo(a)(s3) +; RV32I-NEXT: addi a0, a0, -1 +; RV32I-NEXT: sw a0, %lo(a)(s3) +; RV32I-NEXT: bnez a0, .LBB0_2 +; RV32I-NEXT: .LBB0_11: # %for.end +; RV32I-NEXT: addi a0, zero, 1 +; RV32I-NEXT: lw s11, 16(sp) +; RV32I-NEXT: lw s10, 20(sp) +; RV32I-NEXT: lw s9, 24(sp) +; RV32I-NEXT: lw s8, 28(sp) +; RV32I-NEXT: lw s7, 32(sp) +; RV32I-NEXT: lw s6, 36(sp) +; RV32I-NEXT: lw s5, 40(sp) +; RV32I-NEXT: lw s4, 44(sp) +; RV32I-NEXT: lw s3, 48(sp) +; RV32I-NEXT: lw s2, 52(sp) +; RV32I-NEXT: lw s1, 56(sp) +; RV32I-NEXT: lw ra, 60(sp) +; RV32I-NEXT: addi sp, sp, 64 +; RV32I-NEXT: ret +entry: + %.pr = load i32, i32* @a, align 4 + %tobool14 = icmp eq i32 %.pr, 0 + br i1 %tobool14, label %for.end, label %for.body + +for.body: ; preds = %entry, %for.inc + %0 = phi i32 [ %dec, %for.inc ], [ %.pr, %entry ] + %1 = load i32, i32* @l, align 4 + %tobool1 = icmp eq i32 %1, 0 + br i1 %tobool1, label %if.end, label %if.then + +if.then: ; preds = %for.body + %2 = load i32, i32* @b, align 4 + %3 = load i32, i32* @c, align 4 + %4 = load i32, i32* @d, align 4 + %5 = load i32, i32* @e, align 4 + %call = tail call i32 @foo(i32 %0, i32 %2, i32 %3, i32 %4, i32 %5, i32 32) #3 + br label %if.end + +if.end: ; preds = %for.body, %if.then + %6 = load i32, i32* @k, align 4 + %tobool2 = icmp eq i32 %6, 0 + br i1 %tobool2, label %if.end5, label %if.then3 + +if.then3: ; preds = %if.end + %7 = load i32, i32* @b, align 4 + %8 = load i32, i32* @c, align 4 + %9 = load i32, i32* @d, align 4 + %10 = load i32, i32* @e, align 4 + %11 = load i32, i32* @f, align 4 + %call4 = tail call i32 @foo(i32 %7, i32 %8, i32 %9, i32 %10, i32 %11, i32 64) #3 + br label %if.end5 + +if.end5: ; preds = %if.end, %if.then3 + %12 = load i32, i32* @j, align 4 + %tobool6 = icmp eq i32 %12, 0 + br i1 %tobool6, label %if.end9, label %if.then7 + +if.then7: ; preds = %if.end5 + %13 = load i32, i32* @c, align 4 + %14 = load i32, i32* @d, align 4 + %15 = load i32, i32* @e, align 4 + %16 = load i32, i32* @f, align 4 + %17 = load i32, i32* @g, align 4 + %call8 = tail call i32 @foo(i32 %13, i32 %14, i32 %15, i32 %16, i32 %17, i32 32) #3 + br label %if.end9 + +if.end9: ; preds = %if.end5, %if.then7 + %18 = load i32, i32* @i, align 4 + %tobool10 = icmp eq i32 %18, 0 + br i1 %tobool10, label %for.inc, label %if.then11 + +if.then11: ; preds = %if.end9 + %19 = load i32, i32* @d, align 4 + %20 = load i32, i32* @e, align 4 + %21 = load i32, i32* @f, align 4 + %22 = load i32, i32* @g, align 4 + %23 = load i32, i32* @h, align 4 + %call12 = tail call i32 @foo(i32 %19, i32 %20, i32 %21, i32 %22, i32 %23, i32 32) #3 + br label %for.inc + +for.inc: ; preds = %if.end9, %if.then11 + %24 = load i32, i32* @a, align 4 + %dec = add nsw i32 %24, -1 + store i32 %dec, i32* @a, align 4 + %tobool = icmp eq i32 %dec, 0 + br i1 %tobool, label %for.end, label %for.body + +for.end: ; preds = %for.inc, %entry + ret i32 1 +} + +declare i32 @foo(i32, i32, i32, i32, i32, i32)