[llvm] 4ae2222 - [RISCV] Add a test case to show the bug in RISCVFrameLowering.

[Hsiangkai Wang via llvm-commits]

Author: Hsiangkai Wang
Date: 2021-11-30T10:39:34+08:00
New Revision: 4ae2222e143b8541b6567f9852d9600a17cc9426

URL: https://github.com/llvm/llvm-project/commit/4ae2222e143b8541b6567f9852d9600a17cc9426
DIFF: https://github.com/llvm/llvm-project/commit/4ae2222e143b8541b6567f9852d9600a17cc9426.diff

LOG: [RISCV] Add a test case to show the bug in RISCVFrameLowering.

If the number of arguments is too large to use register passing, it
needs to occupy stack space to pass the arguments to the callee. There
are two scenarios. One is to reserve the space in prologue and the other
is to reserve the space before the function calls. When we need to
reserve the stack space before function calls, the stack pointer is
adjusted. Under the scenario, we should not use stack pointer to access
the stack objects. It looks like,

callseq_start  ->  sp = sp - reserved_space
//
// We should not use SP to access stack objects in this area.
//
call @foo
callseq_end    ->  sp = sp + reserved_space

Differential Revision: https://reviews.llvm.org/D114245

Added: 
    llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll b/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll
new file mode 100644
index 0000000000000..5c88eba7cf8f2
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/no-reserved-frame.ll
@@ -0,0 +1,81 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv64 -mattr=+experimental-v -verify-machineinstrs \
+; RUN:   < %s | FileCheck %s
+
+define signext i32 @foo(i32 signext %aa) #0 {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addi sp, sp, -64
+; CHECK-NEXT:    .cfi_def_cfa_offset 64
+; CHECK-NEXT:    sd ra, 56(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s0, 48(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_offset ra, -8
+; CHECK-NEXT:    .cfi_offset s0, -16
+; CHECK-NEXT:    addi s0, sp, 64
+; CHECK-NEXT:    .cfi_def_cfa s0, 0
+; CHECK-NEXT:    csrr a1, vlenb
+; CHECK-NEXT:    sub sp, sp, a1
+; CHECK-NEXT:    andi sp, sp, -8
+; CHECK-NEXT:    lw t0, 36(sp)
+; CHECK-NEXT:    lw a2, 32(sp)
+; CHECK-NEXT:    lw a3, 28(sp)
+; CHECK-NEXT:    lw a4, 24(sp)
+; CHECK-NEXT:    lw a5, 20(sp)
+; CHECK-NEXT:    lw a6, 16(sp)
+; CHECK-NEXT:    lw a7, 12(sp)
+; CHECK-NEXT:    lw t1, 8(sp)
+; CHECK-NEXT:    lw t2, 4(sp)
+; CHECK-NEXT:    lw a1, 0(sp)
+; CHECK-NEXT:    sw a0, 44(sp)
+; CHECK-NEXT:    sw a0, 40(sp)
+; CHECK-NEXT:    addi sp, sp, -32
+; CHECK-NEXT:    sd a1, 16(sp)
+; CHECK-NEXT:    sd t2, 8(sp)
+; CHECK-NEXT:    addi a1, sp, 40
+; This is the incorrect calculation. It's after the addi sp, sp, -32. The 40
+; doesn't consider the -32 adjustment that was made.
+; CHECK-NEXT:    sd t1, 0(sp)
+; CHECK-NEXT:    mv a0, t0
+; CHECK-NEXT:    call gfunc at plt
+; CHECK-NEXT:    addi sp, sp, 32
+; CHECK-NEXT:    li a0, 0
+; CHECK-NEXT:    addi sp, s0, -64
+; CHECK-NEXT:    ld ra, 56(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s0, 48(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    addi sp, sp, 64
+; CHECK-NEXT:    ret
+entry:
+  %aa.addr = alloca i32, align 4
+  %local = alloca i32, align 4
+  %a = alloca i32, align 4
+  %b = alloca i32, align 4
+  %c = alloca i32, align 4
+  %d = alloca i32, align 4
+  %e = alloca i32, align 4
+  %f = alloca i32, align 4
+  %g = alloca i32, align 4
+  %h = alloca i32, align 4
+  %i = alloca i32, align 4
+  %j = alloca i32, align 4
+  %local_v = alloca <vscale x 2 x i32>, align 4
+  store i32 %aa, i32* %aa.addr, align 4
+  %0 = load i32, i32* %aa.addr, align 4
+  store i32 %0, i32* %local, align 4
+  %1 = load i32, i32* %a, align 4
+  %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
+  %6 = load i32, i32* %f, align 4
+  %7 = load i32, i32* %g, align 4
+  %8 = load i32, i32* %h, align 4
+  %9 = load i32, i32* %i, align 4
+  %10 = load i32, i32* %j, align 4
+  call void @gfunc(i32 signext %1, i32* %local, i32 signext %2, i32 signext %3, i32 signext %4, i32 signext %5, i32 signext %6, i32 signext %7, i32 %8, i32 %9, i32 %10)
+  ret i32 0
+}
+
+declare void @gfunc(i32 signext, i32*, i32 signext, i32 signext, i32 signext, i32 signext, i32 signext, i32 signext, i32, i32, i32) #1
+
+attributes #0 = { "stackrealign" }
+attributes #1 = { "stackrealign" }