[DAG] Update test case for Issue llvm#69965

The previous reduced test case just showed a minor codegen regression, this test now shows the actual miscompilation

Author: RKSimon

llvm/test/CodeGen/X86/pr69965.ll

@@ -2,40 +2,50 @@
 ; RUN: llc < %s -mtriple=i686-- | FileCheck %s --check-prefix=X86
 ; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s --check-prefix=X64
 
-define i16 @test(i8 %_in) {
-; X86-LABEL: test:
-; X86:       # %bb.0:
-; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    notb %al
-; X86-NEXT:    movl %eax, %ecx
-; X86-NEXT:    orb $-128, %cl
-; X86-NEXT:    movzbl %cl, %ecx
-; X86-NEXT:    shll $8, %ecx
-; X86-NEXT:    addb %al, %al
-; X86-NEXT:    movzbl %al, %eax
-; X86-NEXT:    orl %ecx, %eax
-; X86-NEXT:    # kill: def $ax killed $ax killed $eax
+define i64 @PR69965(ptr %input_ptrs, ptr %output_ptrs) {
+; X86-LABEL: PR69965:
+; X86:       # %bb.0: # %entry
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl (%eax), %eax
+; X86-NEXT:    movzbl (%eax), %eax
+; X86-NEXT:    notl %eax
+; X86-NEXT:    movzbl %al, %edx
+; X86-NEXT:    shll $8, %eax
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    leal (%eax,%edx,2), %eax
+; X86-NEXT:    orl $32768, %eax # imm = 0x8000
+; X86-NEXT:    movw %ax, (%ecx)
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    xorl %edx, %edx
 ; X86-NEXT:    retl
 ;
-; X64-LABEL: test:
-; X64:       # %bb.0:
-; X64-NEXT:    notb %dil
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    orb $-128, %al
+; X64-LABEL: PR69965:
+; X64:       # %bb.0: # %entry
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    movzbl (%rax), %eax
+; X64-NEXT:    notl %eax
 ; X64-NEXT:    movzbl %al, %ecx
-; X64-NEXT:    shll $8, %ecx
-; X64-NEXT:    addb %dil, %dil
-; X64-NEXT:    movzbl %dil, %eax
-; X64-NEXT:    orl %ecx, %eax
-; X64-NEXT:    # kill: def $ax killed $ax killed $eax
+; X64-NEXT:    # kill: def $eax killed $eax def $rax
+; X64-NEXT:    shll $8, %eax
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    leal (%rax,%rcx,2), %eax
+; X64-NEXT:    orl $32768, %eax # imm = 0x8000
+; X64-NEXT:    movw %ax, (%rdx)
+; X64-NEXT:    xorl %eax, %eax
 ; X64-NEXT:    retq
-  %_1 = and i8 %_in, 127
-  %_2 = xor i8 %_1, 127
-  %_3 = or i8 %_2, -128
-  %_4 = zext i8 %_3 to i16
-  %_6 = shl nuw i16 %_4, 8
-  %_7 = shl nuw i8 %_2, 1
-  %_8 = zext i8 %_7 to i16
-  %_9 = or i16 %_6, %_8
-  ret i16 %_9
+entry:
+  %0 = load ptr, ptr %input_ptrs, align 8
+  %.val.i = load i8, ptr %0, align 1
+  %1 = and i8 %.val.i, 127
+  %2 = xor i8 %1, 127
+  %3 = or i8 %2, -128
+  %4 = zext i8 %3 to i16
+  %5 = load ptr, ptr %output_ptrs, align 8
+  %6 = shl nuw i16 %4, 8
+  %7 = shl nuw i8 %2, 1
+  %8 = zext i8 %7 to i16
+  %9 = or i16 %6, %8
+  store i16 %9, ptr %5, align 2
+  ret i64 0
 }