[llvm] r250910 - [x86] add test case that shows holes in LEA isel

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Wed Oct 21 12:24:00 2015
New Revision: 250910

URL: http://llvm.org/viewvc/llvm-project?rev=250910&view=rev
Log:
[x86] add test case that shows holes in LEA isel

Added:
    llvm/trunk/test/CodeGen/X86/or-lea.ll

Added: llvm/trunk/test/CodeGen/X86/or-lea.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/or-lea.ll?rev=250910&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/or-lea.ll (added)
+++ llvm/trunk/test/CodeGen/X86/or-lea.ll Wed Oct 21 12:24:00 2015
@@ -0,0 +1,125 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s
+
+; InstCombine and DAGCombiner transform an 'add' into an 'or'
+; if there are no common bits from the incoming operands.
+; LEA instruction selection should be able to see through that
+; transform and reduce add/shift/or instruction counts.
+
+define i32 @or_shift1_and1(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift1_and1:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    addl %edi, %edi
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    leal (%rsi,%rdi), %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 1
+  %and = and i32 %y, 1
+  %or = or i32 %and, %shl
+  ret i32 %or
+}
+
+define i32 @or_shift1_and1_swapped(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift1_and1_swapped:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    leal (%rdi,%rdi), %eax
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    orl %esi, %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 1
+  %and = and i32 %y, 1
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+define i32 @or_shift2_and1(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift2_and1:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    leal (,%rdi,4), %eax
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    orl %esi, %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 2
+  %and = and i32 %y, 1
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+define i32 @or_shift3_and1(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift3_and1:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    leal (,%rdi,8), %eax
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    orl %esi, %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 3
+  %and = and i32 %y, 1
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+define i32 @or_shift3_and7(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift3_and7:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    leal (,%rdi,8), %eax
+; CHECK-NEXT:    andl $7, %esi
+; CHECK-NEXT:    orl %esi, %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 3
+  %and = and i32 %y, 7
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+; The shift is too big for an LEA.
+
+define i32 @or_shift4_and1(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift4_and1:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    shll $4, %edi
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    leal (%rsi,%rdi), %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 4
+  %and = and i32 %y, 1
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+; The mask is too big for the shift, so the 'or' isn't equivalent to an 'add'.
+
+define i32 @or_shift3_and8(i32 %x, i32 %y) {
+; CHECK-LABEL: or_shift3_and8:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    leal (,%rdi,8), %eax
+; CHECK-NEXT:    andl $8, %esi
+; CHECK-NEXT:    orl %esi, %eax
+; CHECK-NEXT:    retq
+
+  %shl = shl i32 %x, 3
+  %and = and i32 %y, 8
+  %or = or i32 %shl, %and
+  ret i32 %or
+}
+
+; 64-bit operands should work too.
+
+define i64 @or_shift1_and1_64(i64 %x, i64 %y) {
+; CHECK-LABEL: or_shift1_and1_64:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    addq %rdi, %rdi
+; CHECK-NEXT:    andl $1, %esi
+; CHECK-NEXT:    leaq (%rsi,%rdi), %rax
+; CHECK-NEXT:    retq
+
+  %shl = shl i64 %x, 1
+  %and = and i64 %y, 1
+  %or = or i64 %and, %shl
+  ret i64 %or
+}
+