Commit d37db750 authored by Craig Topper's avatar Craig Topper
Browse files

[InstCombine] Add a test case for suboptimal handling of (double (bitcast (<1... 

[InstCombine] Add a test case for suboptimal handling of (double (bitcast (<1 x i64> (bitcast (x86_mmx)))))

The outer bitcast gets turned into an extractelement and another
bitcast rather than combining away to a single bitcast from mmx
to double.
parent d115b9fd

llvm/test/Transforms/InstCombine/bitcast-vec-canon.ll

+14 −1
Original line number Diff line number Diff line
@@ -49,9 +49,22 @@ define x86_mmx @e(<1 x i64> %y) { 


define <1 x i64> @f(x86_mmx %y) {

; CHECK-LABEL: @f(

; CHECK-NEXT:    [[C:%.*]] = bitcast x86_mmx %y to <1 x i64>

; CHECK-NEXT:    [[C:%.*]] = bitcast x86_mmx [[Y:%.*]] to <1 x i64>

; CHECK-NEXT:    ret <1 x i64> [[C]]

;

  %c = bitcast x86_mmx %y to <1 x i64>

  ret <1 x i64> %c

}



define double @g(x86_mmx %x) {

; CHECK-LABEL: @g(

; CHECK-NEXT:  entry:

; CHECK-NEXT:    [[BC:%.*]] = bitcast x86_mmx %x to <1 x double>

; CHECK-NEXT:    [[TMP0:%.*]] = extractelement <1 x double> [[BC]], i32 0

; CHECK-NEXT:    ret double [[TMP0]]

;

entry:

  %0 = bitcast x86_mmx %x to <1 x i64>

  %1 = bitcast <1 x i64> %0 to double

  ret double %1

}