[llvm] f26ac73 - [X86] Add test case simplified from PR51175. NFC

[Craig Topper via llvm-commits]

Author: Craig Topper
Date: 2021-07-22T23:22:39-07:00
New Revision: f26ac73fa98eb933ee3c9481a6e81f3509c22858

URL: https://github.com/llvm/llvm-project/commit/f26ac73fa98eb933ee3c9481a6e81f3509c22858
DIFF: https://github.com/llvm/llvm-project/commit/f26ac73fa98eb933ee3c9481a6e81f3509c22858.diff

LOG: [X86] Add test case simplified from PR51175. NFC

Added: 
    llvm/test/CodeGen/X86/pr51175.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/CodeGen/X86/pr51175.ll b/llvm/test/CodeGen/X86/pr51175.ll
new file mode 100644
index 000000000000..9800165cc9e7
--- /dev/null
+++ b/llvm/test/CodeGen/X86/pr51175.ll
@@ -0,0 +1,29 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu | FileCheck %s
+
+; The and with -9 has multiple users which prevents
+; SimplifyDemandedBits from touching it. The truncate only
+; demands the lower 8 bits. X86ISelDAGToDAG.cpp wants form
+; a test instruction from the icmp+trunc+and, but needs to
+; mask the -9 to 8 bits since SimplifyDemandedBits didn't.
+
+define i32 @foo(i16 signext %0, i32 %1, i32* nocapture %2) {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    incl %edi
+; CHECK-NEXT:    movl %edi, %eax
+; CHECK-NEXT:    andl $65527, %eax # imm = 0xFFF7
+; CHECK-NEXT:    movl %eax, (%rdx)
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    testl $-9, %edi
+; CHECK-NEXT:    cmovel %esi, %eax
+; CHECK-NEXT:    retq
+  %4 = add i16 %0, 1
+  %5 = and i16 %4, -9
+  %6 = zext i16 %5 to i32
+  store i32 %6, i32* %2, align 4
+  %7 = trunc i16 %5 to i8
+  %8 = icmp eq i8 %7, 0
+  %9 = select i1 %8, i32 %1, i32 0
+  ret i32 %9
+}