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clang-p2996/llvm/test/CodeGen/X86/bool-math.ll
Sanjay Patel e767bf4468 [DAGCombiner] re-enable truncation of binops 
This is effectively re-committing the changes from:
rL347917 (D54640)
rL348195 (D55126)
...which were effectively reverted here:
rL348604
...because the code had a bug that could induce infinite looping
or eventual out-of-memory compilation.

The bug was that this code did not guard against transforming
opaque constants. More details are in the post-commit mailing
list thread for r347917. A reduced test for that is included
in the x86 bool-math.ll file. (I wasn't able to reduce a PPC
backend test for this, but it was almost the same pattern.)

Original commit message for r347917:

The motivating case for this is shown in:
https://bugs.llvm.org/show_bug.cgi?id=32023
and the corresponding rot16.ll regression tests.

Because x86 scalar shift amounts are i8 values, we can end up with trunc-binop-trunc
sequences that don't get folded in IR.

As the TODO comments suggest, there will be regressions if we extend this (for x86,
we mostly seem to be missing LEA opportunities, but there are likely vector folds
missing too). I think those should be considered existing bugs because this is the
same transform that we do as an IR canonicalization in instcombine. We just need
more tests to make those visible independent of this patch.

llvm-svn: 348706
2018-12-08 16:07:38 +00:00

288 lines
8.1 KiB
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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s --check-prefix=X64
; RUN: llc < %s -mtriple=i686-- | FileCheck %s --check-prefix=X32
define i32 @sub_zext_cmp_mask_same_size_result(i32 %x) {
; X64-LABEL: sub_zext_cmp_mask_same_size_result:
; X64: # %bb.0:
; X64-NEXT: # kill: def $edi killed $edi def $rdi
; X64-NEXT: andl $1, %edi
; X64-NEXT: leal -28(%rdi), %eax
; X64-NEXT: retq
;
; X32-LABEL: sub_zext_cmp_mask_same_size_result:
; X32: # %bb.0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: orl $-28, %eax
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i32
%r = sub i32 -27, %z
ret i32 %r
}
define i32 @sub_zext_cmp_mask_wider_result(i8 %x) {
; X64-LABEL: sub_zext_cmp_mask_wider_result:
; X64: # %bb.0:
; X64-NEXT: # kill: def $edi killed $edi def $rdi
; X64-NEXT: andl $1, %edi
; X64-NEXT: leal 26(%rdi), %eax
; X64-NEXT: retq
;
; X32-LABEL: sub_zext_cmp_mask_wider_result:
; X32: # %bb.0:
; X32-NEXT: movzbl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: orl $26, %eax
; X32-NEXT: retl
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i32
%r = sub i32 27, %z
ret i32 %r
}
define i8 @sub_zext_cmp_mask_narrower_result(i32 %x) {
; X64-LABEL: sub_zext_cmp_mask_narrower_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andb $1, %al
; X64-NEXT: orb $46, %al
; X64-NEXT: # kill: def $al killed $al killed $eax
; X64-NEXT: retq
;
; X32-LABEL: sub_zext_cmp_mask_narrower_result:
; X32: # %bb.0:
; X32-NEXT: movb {{[0-9]+}}(%esp), %al
; X32-NEXT: andb $1, %al
; X32-NEXT: orb $46, %al
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i8
%r = sub i8 47, %z
ret i8 %r
}
define i8 @add_zext_cmp_mask_same_size_result(i8 %x) {
; X64-LABEL: add_zext_cmp_mask_same_size_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andb $1, %al
; X64-NEXT: xorb $27, %al
; X64-NEXT: # kill: def $al killed $al killed $eax
; X64-NEXT: retq
;
; X32-LABEL: add_zext_cmp_mask_same_size_result:
; X32: # %bb.0:
; X32-NEXT: movb {{[0-9]+}}(%esp), %al
; X32-NEXT: andb $1, %al
; X32-NEXT: xorb $27, %al
; X32-NEXT: retl
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i8
%r = add i8 %z, 26
ret i8 %r
}
define i32 @add_zext_cmp_mask_wider_result(i8 %x) {
; X64-LABEL: add_zext_cmp_mask_wider_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andl $1, %eax
; X64-NEXT: xorl $27, %eax
; X64-NEXT: retq
;
; X32-LABEL: add_zext_cmp_mask_wider_result:
; X32: # %bb.0:
; X32-NEXT: movzbl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: xorl $27, %eax
; X32-NEXT: retl
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%z = zext i1 %c to i32
%r = add i32 %z, 26
ret i32 %r
}
define i8 @add_zext_cmp_mask_narrower_result(i32 %x) {
; X64-LABEL: add_zext_cmp_mask_narrower_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andb $1, %al
; X64-NEXT: xorb $43, %al
; X64-NEXT: # kill: def $al killed $al killed $eax
; X64-NEXT: retq
;
; X32-LABEL: add_zext_cmp_mask_narrower_result:
; X32: # %bb.0:
; X32-NEXT: movb {{[0-9]+}}(%esp), %al
; X32-NEXT: andb $1, %al
; X32-NEXT: xorb $43, %al
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%z = zext i1 %c to i8
%r = add i8 %z, 42
ret i8 %r
}
define i32 @low_bit_select_constants_bigger_false_same_size_result(i32 %x) {
; X64-LABEL: low_bit_select_constants_bigger_false_same_size_result:
; X64: # %bb.0:
; X64-NEXT: # kill: def $edi killed $edi def $rdi
; X64-NEXT: andl $1, %edi
; X64-NEXT: leal 42(%rdi), %eax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_false_same_size_result:
; X32: # %bb.0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: orl $42, %eax
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%r = select i1 %c, i32 42, i32 43
ret i32 %r
}
define i64 @low_bit_select_constants_bigger_false_wider_result(i32 %x) {
; X64-LABEL: low_bit_select_constants_bigger_false_wider_result:
; X64: # %bb.0:
; X64-NEXT: # kill: def $edi killed $edi def $rdi
; X64-NEXT: andl $1, %edi
; X64-NEXT: leaq 26(%rdi), %rax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_false_wider_result:
; X32: # %bb.0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: orl $26, %eax
; X32-NEXT: xorl %edx, %edx
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%r = select i1 %c, i64 26, i64 27
ret i64 %r
}
define i16 @low_bit_select_constants_bigger_false_narrower_result(i32 %x) {
; X64-LABEL: low_bit_select_constants_bigger_false_narrower_result:
; X64: # %bb.0:
; X64-NEXT: # kill: def $edi killed $edi def $rdi
; X64-NEXT: andl $1, %edi
; X64-NEXT: leal 36(%rdi), %eax
; X64-NEXT: # kill: def $ax killed $ax killed $eax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_false_narrower_result:
; X32: # %bb.0:
; X32-NEXT: movzwl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: orl $36, %eax
; X32-NEXT: # kill: def $ax killed $ax killed $eax
; X32-NEXT: retl
%a = and i32 %x, 1
%c = icmp eq i32 %a, 0
%r = select i1 %c, i16 36, i16 37
ret i16 %r
}
define i8 @low_bit_select_constants_bigger_true_same_size_result(i8 %x) {
; X64-LABEL: low_bit_select_constants_bigger_true_same_size_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andb $1, %al
; X64-NEXT: xorb $-29, %al
; X64-NEXT: # kill: def $al killed $al killed $eax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_true_same_size_result:
; X32: # %bb.0:
; X32-NEXT: movb {{[0-9]+}}(%esp), %al
; X32-NEXT: andb $1, %al
; X32-NEXT: xorb $-29, %al
; X32-NEXT: retl
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i8 227, i8 226
ret i8 %r
}
define i32 @low_bit_select_constants_bigger_true_wider_result(i8 %x) {
; X64-LABEL: low_bit_select_constants_bigger_true_wider_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andl $1, %eax
; X64-NEXT: xorl $227, %eax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_true_wider_result:
; X32: # %bb.0:
; X32-NEXT: movzbl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: xorl $227, %eax
; X32-NEXT: retl
%a = and i8 %x, 1
%c = icmp eq i8 %a, 0
%r = select i1 %c, i32 227, i32 226
ret i32 %r
}
define i8 @low_bit_select_constants_bigger_true_narrower_result(i16 %x) {
; X64-LABEL: low_bit_select_constants_bigger_true_narrower_result:
; X64: # %bb.0:
; X64-NEXT: movl %edi, %eax
; X64-NEXT: andb $1, %al
; X64-NEXT: xorb $41, %al
; X64-NEXT: # kill: def $al killed $al killed $eax
; X64-NEXT: retq
;
; X32-LABEL: low_bit_select_constants_bigger_true_narrower_result:
; X32: # %bb.0:
; X32-NEXT: movb {{[0-9]+}}(%esp), %al
; X32-NEXT: andb $1, %al
; X32-NEXT: xorb $41, %al
; X32-NEXT: retl
%a = and i16 %x, 1
%c = icmp eq i16 %a, 0
%r = select i1 %c, i8 41, i8 40
ret i8 %r
}
; Truncation hoisting must not occur with opaque constants
; because that can induce infinite looping.
define i1 @opaque_constant(i48 %x, i48 %y) {
; X64-LABEL: opaque_constant:
; X64: # %bb.0:
; X64-NEXT: movq %rsi, %rax
; X64-NEXT: shrq $32, %rdi
; X64-NEXT: shrq $32, %rax
; X64-NEXT: xorl %edi, %eax
; X64-NEXT: andl $1, %eax
; X64-NEXT: # kill: def $al killed $al killed $rax
; X64-NEXT: retq
;
; X32-LABEL: opaque_constant:
; X32: # %bb.0:
; X32-NEXT: movl {{[0-9]+}}(%esp), %eax
; X32-NEXT: xorl {{[0-9]+}}(%esp), %eax
; X32-NEXT: andl $1, %eax
; X32-NEXT: # kill: def $al killed $al killed $eax
; X32-NEXT: retl
%andx = and i48 %x, 4294967296
%andy = and i48 %y, 4294967296
%cmp1 = icmp ne i48 %andx, 0
%cmp2 = icmp ne i48 %andy, 0
%r = xor i1 %cmp1, %cmp2
ret i1 %r
}
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