[llvm] r307819 - [x86] add tests for improving sbb transforms; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Wed Jul 12 10:44:50 2017
New Revision: 307819

URL: http://llvm.org/viewvc/llvm-project?rev=307819&view=rev
Log:
[x86] add tests for improving sbb transforms; NFC

We're subtracting X from X the hard way...


Modified:
    llvm/trunk/test/CodeGen/X86/sbb.ll

Modified: llvm/trunk/test/CodeGen/X86/sbb.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/sbb.ll?rev=307819&r1=307818&r2=307819&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/sbb.ll (original)
+++ llvm/trunk/test/CodeGen/X86/sbb.ll Wed Jul 12 10:44:50 2017
@@ -185,6 +185,41 @@ define i32 @uge_select_0_or_neg1_sub(i32
   ret i32 %sub
 }
 
+; Check more sub-from-zero patterns.
+; (X >u Y) ? -1 : 0  --> cmp, sbb
+
+define i64 @ugt_select_neg1_or_0_sub(i64 %x, i64 %y) nounwind {
+; CHECK-LABEL: ugt_select_neg1_or_0_sub:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    cmpq %rdi, %rsi
+; CHECK-NEXT:    sbbq $0, %rax
+; CHECK-NEXT:    retq
+  %cmp = icmp ugt i64 %x, %y
+  %zext = zext i1 %cmp to i64
+  %sub = sub i64 0, %zext
+  ret i64 %sub
+}
+
+; Swap the predicate and compare operands:
+; (Y <u X) ? -1 : 0  --> cmp, sbb
+
+define i16 @ult_select_neg1_or_0_sub(i16 %x, i16 %y) nounwind {
+; CHECK-LABEL: ult_select_neg1_or_0_sub:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    cmpw %di, %si
+; CHECK-NEXT:    sbbl $0, %eax
+; CHECK-NEXT:    # kill: %AX<def> %AX<kill> %EAX<kill>
+; CHECK-NEXT:    retq
+  %cmp = icmp ult i16 %y, %x
+  %zext = zext i1 %cmp to i16
+  %sub = sub i16 0, %zext
+  ret i16 %sub
+}
+
+
+
 ; Make sure we're creating nodes with the right value types. This would crash.
 ; https://bugs.llvm.org/show_bug.cgi?id=33560