llvm-6502/test/CodeGen/X86/lower-bitcast.ll
Chandler Carruth d24d326705 [SDAG] Introduce a combined set to the DAG combiner which tracks nodes
which have successfully round-tripped through the combine phase, and use
this to ensure all operands to DAG nodes are visited by the combiner,
even if they are only added during the combine phase.

This is critical to have the combiner reach nodes that are *introduced*
during combining. Previously these would sometimes be visited and
sometimes not be visited based on whether they happened to end up on the
worklist or not. Now we always run them through the combiner.

This fixes quite a few bad codegen test cases lurking in the suite while
also being more principled. Among these, the TLS codegeneration is
particularly exciting for programs that have this in the critical path
like TSan-instrumented binaries (although I think they engineer to use
a different TLS that is faster anyways).

I've tried to check for compile-time regressions here by running llc
over a merged (but not LTO-ed) clang bitcode file and observed at most
a 3% slowdown in llc. Given that this is essentially a worst case (none
of opt or clang are running at this phase) I think this is tolerable.
The actual LTO case should be even less costly, and the cost in normal
compilation should be negligible.

With this combining logic, it is possible to re-legalize as we combine
which is necessary to implement PSHUFB formation on x86 as
a post-legalize DAG combine (my ultimate goal).

Differential Revision: http://reviews.llvm.org/D4638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213898 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-24 22:15:28 +00:00

189 lines
4.4 KiB
LLVM

; RUN: llc < %s -march=x86-64 -mcpu=core2 -mattr=+sse2 | FileCheck %s
; RUN: llc < %s -march=x86-64 -mcpu=core2 -mattr=+sse2 -x86-experimental-vector-widening-legalization | FileCheck %s --check-prefix=CHECK-WIDE
define double @test1(double %A) {
%1 = bitcast double %A to <2 x i32>
%add = add <2 x i32> %1, <i32 3, i32 5>
%2 = bitcast <2 x i32> %add to double
ret double %2
}
; FIXME: Ideally we should be able to fold the entire body of @test1 into a
; single paddd instruction. At the moment we produce the sequence
; pshufd+paddq+pshufd. This is fixed with the widening legalization.
;
; CHECK-LABEL: test1
; CHECK-NOT: movsd
; CHECK: pshufd
; CHECK-NEXT: paddd
; CHECK-NEXT: pshufd
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test1
; CHECK-WIDE-NOT: movsd
; CHECK-WIDE: paddd
; CHECK-WIDE-NEXT: ret
define double @test2(double %A, double %B) {
%1 = bitcast double %A to <2 x i32>
%2 = bitcast double %B to <2 x i32>
%add = add <2 x i32> %1, %2
%3 = bitcast <2 x i32> %add to double
ret double %3
}
; CHECK-LABEL: test2
; CHECK-NOT: movsd
; CHECK: paddd
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test2
; CHECK-WIDE-NOT: movsd
; CHECK-WIDE: paddd
; CHECK-WIDE-NEXT: ret
define i64 @test3(i64 %A) {
%1 = bitcast i64 %A to <2 x float>
%add = fadd <2 x float> %1, <float 3.0, float 5.0>
%2 = bitcast <2 x float> %add to i64
ret i64 %2
}
; CHECK-LABEL: test3
; CHECK-NOT: pshufd
; CHECK: addps
; CHECK-NOT: pshufd
; CHECK: ret
;
; CHECK-WIDE-LABEL: test3
; CHECK-WIDE-NOT: pshufd
; CHECK-WIDE: addps
; CHECK-WIDE-NOT: pshufd
; CHECK-WIDE: ret
define i64 @test4(i64 %A) {
%1 = bitcast i64 %A to <2 x i32>
%add = add <2 x i32> %1, <i32 3, i32 5>
%2 = bitcast <2 x i32> %add to i64
ret i64 %2
}
; FIXME: At the moment we still produce the sequence pshufd+paddd+pshufd.
; Ideally, we should fold that sequence into a single paddd. This is fixed with
; the widening legalization.
;
; CHECK-LABEL: test4
; CHECK: pshufd
; CHECK-NEXT: paddd
; CHECK-NEXT: pshufd
; CHECK: ret
;
; CHECK-WIDE-LABEL: test4
; CHECK-WIDE: movd %{{rdi|rcx}},
; CHECK-WIDE-NEXT: paddd
; CHECK-WIDE-NEXT: movd {{.*}}, %rax
; CHECK-WIDE: ret
define double @test5(double %A) {
%1 = bitcast double %A to <2 x float>
%add = fadd <2 x float> %1, <float 3.0, float 5.0>
%2 = bitcast <2 x float> %add to double
ret double %2
}
; CHECK-LABEL: test5
; CHECK: addps
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test5
; CHECK-WIDE: addps
; CHECK-WIDE-NEXT: ret
define double @test6(double %A) {
%1 = bitcast double %A to <4 x i16>
%add = add <4 x i16> %1, <i16 3, i16 4, i16 5, i16 6>
%2 = bitcast <4 x i16> %add to double
ret double %2
}
; FIXME: Ideally we should be able to fold the entire body of @test6 into a
; single paddw instruction. This is fixed with the widening legalization.
;
; CHECK-LABEL: test6
; CHECK-NOT: movsd
; CHECK: punpcklwd
; CHECK-NEXT: paddw
; CHECK-NEXT: pshufb
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test6
; CHECK-WIDE-NOT: mov
; CHECK-WIDE-NOT: punpcklwd
; CHECK-WIDE: paddw
; CHECK-WIDE-NEXT: ret
define double @test7(double %A, double %B) {
%1 = bitcast double %A to <4 x i16>
%2 = bitcast double %B to <4 x i16>
%add = add <4 x i16> %1, %2
%3 = bitcast <4 x i16> %add to double
ret double %3
}
; CHECK-LABEL: test7
; CHECK-NOT: movsd
; CHECK-NOT: punpcklwd
; CHECK: paddw
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test7
; CHECK-WIDE-NOT: movsd
; CHECK-WIDE-NOT: punpcklwd
; CHECK-WIDE: paddw
; CHECK-WIDE-NEXT: ret
define double @test8(double %A) {
%1 = bitcast double %A to <8 x i8>
%add = add <8 x i8> %1, <i8 3, i8 4, i8 5, i8 6, i8 7, i8 8, i8 9, i8 10>
%2 = bitcast <8 x i8> %add to double
ret double %2
}
; FIXME: Ideally we should be able to fold the entire body of @test8 into a
; single paddb instruction. At the moment we produce the sequence
; pshufd+paddw+pshufd. This is fixed with the widening legalization.
;
; CHECK-LABEL: test8
; CHECK-NOT: movsd
; CHECK: punpcklbw
; CHECK-NEXT: paddb
; CHECK-NEXT: pshufb
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test8
; CHECK-WIDE-NOT: movsd
; CHECK-WIDE-NOT: punpcklbw
; CHECK-WIDE: paddb
; CHECK-WIDE-NEXT: ret
define double @test9(double %A, double %B) {
%1 = bitcast double %A to <8 x i8>
%2 = bitcast double %B to <8 x i8>
%add = add <8 x i8> %1, %2
%3 = bitcast <8 x i8> %add to double
ret double %3
}
; CHECK-LABEL: test9
; CHECK-NOT: movsd
; CHECK-NOT: punpcklbw
; CHECK: paddb
; CHECK-NEXT: ret
;
; CHECK-WIDE-LABEL: test9
; CHECK-WIDE-NOT: movsd
; CHECK-WIDE-NOT: punpcklbw
; CHECK-WIDE: paddb
; CHECK-WIDE-NEXT: ret