Extend the r107852 optimization which turns some fp compare to code sequence using only i32 operations. It now optimize some f64 compares when fp compare is exceptionally slow (e.g. cortex-a8). It also catches comparison against 0.0.

llvm-svn: 108258

1 files changed, 62 insertions, 9 deletions

diff --git a/llvm/test/CodeGen/ARM/fpcmp-opt.ll b/llvm/test/CodeGen/ARM/fpcmp-opt.ll
index 8016033b1fb..6875288304b 100644
--- a/llvm/test/CodeGen/ARM/fpcmp-opt.ll
+++ b/llvm/test/CodeGen/ARM/fpcmp-opt.ll
@@ -1,16 +1,24 @@
-; RUN: llc < %s -march=arm -mattr=+vfp2 -enable-unsafe-fp-math -enable-finite-only-fp-math | FileCheck %s
+; RUN: llc < %s -march=arm -mcpu=cortex-a8 -mattr=+vfp2 -enable-unsafe-fp-math -enable-finite-only-fp-math | FileCheck -check-prefix=FINITE %s
+; RUN: llc < %s -march=arm -mcpu=cortex-a8 -mattr=+vfp2 -enable-unsafe-fp-math | FileCheck -check-prefix=NAN %s
 ; rdar://7461510
 
 define arm_apcscc i32 @t1(float* %a, float* %b) nounwind {
 entry:
-; CHECK: t1:
-; CHECK-NOT: vldr
-; CHECK: ldr
-; CHECK: ldr
-; CHECK: cmp r0, r1
-; CHECK-NOT: vcmpe.f32
-; CHECK-NOT: vmrs
-; CHECK: beq
+; FINITE: t1:
+; FINITE-NOT: vldr
+; FINITE: ldr
+; FINITE: ldr
+; FINITE: cmp r0, r1
+; FINITE-NOT: vcmpe.f32
+; FINITE-NOT: vmrs
+; FINITE: beq
+
+; NAN: t1:
+; NAN: vldr.32 s0,
+; NAN: vldr.32 s1,
+; NAN: vcmpe.f32 s1, s0
+; NAN: vmrs apsr_nzcv, fpscr
+; NAN: beq
   %0 = load float* %a
   %1 = load float* %b
   %2 = fcmp une float %0, %1
@@ -25,5 +33,50 @@ bb2:
   ret i32 %4
 }
 
+define arm_apcscc i32 @t2(double* %a, double* %b) nounwind {
+entry:
+; FINITE: t2:
+; FINITE-NOT: vldr
+; FINITE: ldrd r0, [r0]
+; FINITE: cmp r0, #0
+; FINITE: cmpeq r1, #0
+; FINITE-NOT: vcmpe.f32
+; FINITE-NOT: vmrs
+; FINITE: bne
+  %0 = load double* %a
+  %1 = fcmp oeq double %0, 0.000000e+00
+  br i1 %1, label %bb1, label %bb2
+
+bb1:
+  %2 = call i32 @bar()
+  ret i32 %2
+
+bb2:
+  %3 = call i32 @foo()
+  ret i32 %3
+}
+
+define arm_apcscc i32 @t3(float* %a, float* %b) nounwind {
+entry:
+; FINITE: t3:
+; FINITE-NOT: vldr
+; FINITE: ldr r0, [r0]
+; FINITE: cmp r0, #0
+; FINITE-NOT: vcmpe.f32
+; FINITE-NOT: vmrs
+; FINITE: bne
+  %0 = load float* %a
+  %1 = fcmp oeq float %0, 0.000000e+00
+  br i1 %1, label %bb1, label %bb2
+
+bb1:
+  %2 = call i32 @bar()
+  ret i32 %2
+
+bb2:
+  %3 = call i32 @foo()
+  ret i32 %3
+}
+
 declare i32 @bar()
 declare i32 @foo()