Provide InstCombines for the following 3 cases:

A * (1 - (uitofp i1 C)) -> select C, 0, A
B * (uitofp i1 C) -> select C, B, 0
select C, 0, A + select C, B, 0 -> select C, B, A

These come up in code that has been hand-optimized from a select to a linear blend, 
on platforms where that may have mattered. We want to undo such changes 
with the following transform:
A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181216 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/add4.ll b/test/Transforms/InstCombine/add4.ll
new file mode 100644
index 0000000..9cc24e9
--- /dev/null
+++ b/test/Transforms/InstCombine/add4.ll
@@ -0,0 +1,34 @@
+; RUN: opt < %s -instcombine -S | grep inttoptr | count 2
+
+;; Target triple for gep raising case below.
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i686-apple-darwin8"
+
+define float @test1(float %A, float %B, i1 %C) {
+EntryBlock:
+  ;; A*(1 - uitofp i1 C) -> select C, 0, A
+  %cf = uitofp i1 %C to float
+  %mc = fsub float 1.000000e+00, %cf
+  %p1 = fmul fast float %A, %mc
+  ret float %p1
+}
+
+define float @test2(float %A, float %B, i1 %C) {
+EntryBlock:
+  ;; B*(uitofp i1 C) -> select C, B, 0
+  %cf = uitofp i1 %C to float
+  %p2 = fmul fast float %B, %cf
+  ret float %p2
+}
+
+define float @test3(float %A, float %B, i1 %C) {
+EntryBlock:
+  ;; A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B
+  %cf = uitofp i1 %C to float
+  %mc = fsub float 1.000000e+00, %cf
+  %p1 = fmul fast float %A, %mc
+  %p2 = fmul fast float %B, %cf
+  %s1 = fadd fast float %p1, %p2
+  ret float %s1
+}
+