llvm/test/Transforms/InstCombine/bitcast-bitcast.ll
Sanjay Patel 63b29821f9 [InstCombine] allow any pair of bitcasts to be combined
This change is discussed in D15392 and should allow us to effectively
revert:
http://llvm.org/viewvc/llvm-project?view=revision&revision=255261
if we canonicalize bitcasts ahead of extracts.

It should be safe to convert any pair of bitcasts into a single bitcast, 
however, it was mentioned here:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20110829/127089.html
that we're not allowed to bitcast from an x86_mmx to some other types, but I'm 
not seeing any failures from that, and we have regression tests in CodeGen/X86
that appear to cover all of those cases. 

Some day we'll get to remove that MMX wart from LLVM IR completely?

Differential Revision: http://reviews.llvm.org/D15468



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255399 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-12 00:33:36 +00:00

85 lines
2.3 KiB
LLVM

; RUN: opt < %s -instcombine -S | FileCheck %s
; Check all scalar / vector combinations for a pair of bitcasts.
define ppc_fp128 @bitcast_bitcast_s_s_s(i128 %a) {
%bc1 = bitcast i128 %a to fp128
%bc2 = bitcast fp128 %bc1 to ppc_fp128
ret ppc_fp128 %bc2
; CHECK-LABEL: @bitcast_bitcast_s_s_s(
; CHECK-NEXT: %bc2 = bitcast i128 %a to ppc_fp128
; CHECK-NEXT: ret ppc_fp128 %bc2
}
define <2 x i32> @bitcast_bitcast_s_s_v(i64 %a) {
%bc1 = bitcast i64 %a to double
%bc2 = bitcast double %bc1 to <2 x i32>
ret <2 x i32> %bc2
; CHECK-LABEL: @bitcast_bitcast_s_s_v(
; CHECK-NEXT: %bc2 = bitcast i64 %a to <2 x i32>
; CHECK-NEXT: ret <2 x i32> %bc2
}
define double @bitcast_bitcast_s_v_s(i64 %a) {
%bc1 = bitcast i64 %a to <2 x i32>
%bc2 = bitcast <2 x i32> %bc1 to double
ret double %bc2
; CHECK-LABEL: @bitcast_bitcast_s_v_s(
; CHECK-NEXT: %bc2 = bitcast i64 %a to double
; CHECK-NEXT: ret double %bc2
}
define <2 x i32> @bitcast_bitcast_s_v_v(i64 %a) {
%bc1 = bitcast i64 %a to <4 x i16>
%bc2 = bitcast <4 x i16> %bc1 to <2 x i32>
ret <2 x i32> %bc2
; CHECK-LABEL: @bitcast_bitcast_s_v_v(
; CHECK-NEXT: %bc2 = bitcast i64 %a to <2 x i32>
; CHECK-NEXT: ret <2 x i32> %bc2
}
define i64 @bitcast_bitcast_v_s_s(<2 x i32> %a) {
%bc1 = bitcast <2 x i32> %a to double
%bc2 = bitcast double %bc1 to i64
ret i64 %bc2
; CHECK-LABEL: @bitcast_bitcast_v_s_s(
; CHECK-NEXT: %bc2 = bitcast <2 x i32> %a to i64
; CHECK-NEXT: ret i64 %bc2
}
define <4 x i16> @bitcast_bitcast_v_s_v(<2 x i32> %a) {
%bc1 = bitcast <2 x i32> %a to double
%bc2 = bitcast double %bc1 to <4 x i16>
ret <4 x i16> %bc2
; CHECK-LABEL: @bitcast_bitcast_v_s_v(
; CHECK-NEXT: %bc2 = bitcast <2 x i32> %a to <4 x i16>
; CHECK-NEXT: ret <4 x i16> %bc2
}
define double @bitcast_bitcast_v_v_s(<2 x float> %a) {
%bc1 = bitcast <2 x float> %a to <4 x i16>
%bc2 = bitcast <4 x i16> %bc1 to double
ret double %bc2
; CHECK-LABEL: @bitcast_bitcast_v_v_s(
; CHECK-NEXT: %bc2 = bitcast <2 x float> %a to double
; CHECK-NEXT: ret double %bc2
}
define <2 x i32> @bitcast_bitcast_v_v_v(<2 x float> %a) {
%bc1 = bitcast <2 x float> %a to <4 x i16>
%bc2 = bitcast <4 x i16> %bc1 to <2 x i32>
ret <2 x i32> %bc2
; CHECK-LABEL: @bitcast_bitcast_v_v_v(
; CHECK-NEXT: %bc2 = bitcast <2 x float> %a to <2 x i32>
; CHECK-NEXT: ret <2 x i32> %bc2
}