[llvm] ba1c773 - [RISCV] Precommit test to show wrong way to pass scalable FP vector on stack

[Kito Cheng via llvm-commits]

Author: Kito Cheng
Date: 2023-03-15T17:21:07+08:00
New Revision: ba1c7731f15bb51253316180330d60f16fe3c5b7

URL: https://github.com/llvm/llvm-project/commit/ba1c7731f15bb51253316180330d60f16fe3c5b7
DIFF: https://github.com/llvm/llvm-project/commit/ba1c7731f15bb51253316180330d60f16fe3c5b7.diff

LOG: [RISCV] Precommit test to show wrong way to pass scalable FP vector on stack

Test case to demo scaleable vector on stack will cause stack corruption.

Detail explan what happened:

```
tail call void @foo(i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0,
                    <vscale x 16 x float> zeroinitializer,
                    <vscale x 16 x float> zeroinitializer,
                    <vscale x 16 x float> zeroinitializer)
```

`foo` take 13 arguments, first 8 argument pass in GPR, and next 2 LMUL 8 vector
arguments passed in v8-v23, and now we run out of argument register for GPR and
vector register, so we must pass last LMUL 8 vector argument by stack.

However LLVM only reserve 8 byte on stack for the LMUL 8 vector
argument, it will cause stack corruption when we try to store that into
stack.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D145934

Added: 
    llvm/test/CodeGen/RISCV/calling-conv-vector-on-stack.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/CodeGen/RISCV/calling-conv-vector-on-stack.ll b/llvm/test/CodeGen/RISCV/calling-conv-vector-on-stack.ll
new file mode 100644
index 000000000000..2138c88c9726
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/calling-conv-vector-on-stack.ll
@@ -0,0 +1,32 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv64 -mattr=+v -verify-machineinstrs -treat-scalable-fixed-error-as-warning < %s 2>&1 | FileCheck %s
+
+; CHECK: warning: Invalid size request on a scalable vector
+
+define void @bar() nounwind {
+; CHECK-LABEL: bar:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    addi sp, sp, -16
+; CHECK-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    vsetvli a0, zero, e32, m8, ta, ma
+; CHECK-NEXT:    vmv.v.i v8, 0
+; CHECK-NEXT:    vs8r.v v8, (sp)
+; CHECK-NEXT:    li a0, 0
+; CHECK-NEXT:    li a1, 0
+; CHECK-NEXT:    li a2, 0
+; CHECK-NEXT:    li a3, 0
+; CHECK-NEXT:    li a4, 0
+; CHECK-NEXT:    li a5, 0
+; CHECK-NEXT:    li a6, 0
+; CHECK-NEXT:    li a7, 0
+; CHECK-NEXT:    vmv.v.i v16, 0
+; CHECK-NEXT:    call foo at plt
+; CHECK-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    addi sp, sp, 16
+; CHECK-NEXT:    ret
+entry:
+  tail call void @foo(i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, <vscale x 16 x float> zeroinitializer, <vscale x 16 x float> zeroinitializer, <vscale x 16 x float> zeroinitializer)
+  ret void
+}
+
+declare void @foo(i32, i32, i32, i32, i32, i32, i32, i32, <vscale x 16 x float>, <vscale x 16 x float>, <vscale x 16 x float>) nounwind