[llvm] r328927 - [X86] Add test case to show failure to promote i16 subtract because we mistakenly believe the load can be folded. NFC

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sat Mar 31 23:29:23 2018
New Revision: 328927

URL: http://llvm.org/viewvc/llvm-project?rev=328927&view=rev
Log:
[X86] Add test case to show failure to promote i16 subtract because we mistakenly believe the load can be folded. NFC

The left hand side of the subtract is a load, but we cna't fold those unless we also have a store.

Modified:
    llvm/trunk/test/CodeGen/X86/promote-i16.ll

Modified: llvm/trunk/test/CodeGen/X86/promote-i16.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/promote-i16.ll?rev=328927&r1=328926&r2=328927&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/promote-i16.ll (original)
+++ llvm/trunk/test/CodeGen/X86/promote-i16.ll Sat Mar 31 23:29:23 2018
@@ -1,23 +1,58 @@
-; RUN: llc < %s -mtriple=i686-unknown-linux-gnu | FileCheck %s
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i686-unknown-linux-gnu | FileCheck %s --check-prefix=X86
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s --check-prefix=X64
 
 define signext i16 @foo(i16 signext %x) nounwind {
+; X86-LABEL: foo:
+; X86:       # %bb.0: # %entry
+; X86-NEXT:    movzwl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    xorl $21998, %eax # imm = 0x55EE
+; X86-NEXT:    # kill: def $ax killed $ax killed $eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: foo:
+; X64:       # %bb.0: # %entry
+; X64-NEXT:    xorl $21998, %edi # imm = 0x55EE
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    retq
 entry:
-; CHECK-LABEL: foo:
-; CHECK: movzwl 4(%esp), %eax
-; CHECK-NEXT: xorl $21998, %eax
-; CHECK-NEXT: # kill
-; CHECK-NEXT: retl
   %0 = xor i16 %x, 21998
   ret i16 %0
 }
 
 define signext i16 @bar(i16 signext %x) nounwind {
+; X86-LABEL: bar:
+; X86:       # %bb.0: # %entry
+; X86-NEXT:    movzwl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    xorl $54766, %eax # imm = 0xD5EE
+; X86-NEXT:    # kill: def $ax killed $ax killed $eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bar:
+; X64:       # %bb.0: # %entry
+; X64-NEXT:    xorl $54766, %edi # imm = 0xD5EE
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    retq
 entry:
-; CHECK-LABEL: bar:
-; CHECK: movzwl 4(%esp), %eax
-; CHECK-NEXT: xorl $54766, %eax
-; CHECK-NEXT: # kill
-; CHECK-NEXT: retl
   %0 = xor i16 %x, 54766
   ret i16 %0
 }
+
+define signext i16 @baz(i16* %x, i16 signext %y) nounwind {
+; X86-LABEL: baz:
+; X86:       # %bb.0: # %entry
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movzwl (%eax), %eax
+; X86-NEXT:    subw {{[0-9]+}}(%esp), %ax
+; X86-NEXT:    retl
+;
+; X64-LABEL: baz:
+; X64:       # %bb.0: # %entry
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    subw %si, %ax
+; X64-NEXT:    retq
+entry:
+  %0 = load i16, i16* %x
+  %sub = sub i16 %0, %y
+  ret i16 %sub
+}