AMDGPU: Fix amdgpu-flat-work-group-size/amdgpu-waves-per-eu check

[arsenm]

LGTM

llvm/trunk/lib/Target/AMDGPU/AMDGPUSubtarget.cpp

if (Requested.first < getMinWavesPerEU() ||
       Requested.first > getMaxWavesPerEU())
     return Default;
   if (Requested.second > getMaxWavesPerEU())
     return Default;
 
   // Make sure requested values are compatible with values implied by requested
   // minimum/maximum flat work group sizes.
   if (RequestedFlatWorkGroupSize &&
-      Requested.first > MinImpliedByFlatWorkGroupSize)
+      Requested.first < MinImpliedByFlatWorkGroupSize)
     return Default;
 
   return Requested;
 }
 
 bool AMDGPUSubtarget::makeLIDRangeMetadata(Instruction *I) const {
   Function *Kernel = I->getParent()->getParent();
   unsigned MinSize = 0;

llvm/trunk/test/CodeGen/AMDGPU/attr-amdgpu-waves-per-eu.ll

define amdgpu_kernel void @exactly_10() #9 {
   store volatile float %val27, float addrspace(1)* @var
   store volatile float %val28, float addrspace(1)* @var
   store volatile float %val29, float addrspace(1)* @var
   store volatile float %val30, float addrspace(1)* @var
 
   ret void
 }
 attributes #9 = {"amdgpu-waves-per-eu"="10,10"}
+
+; Exactly 256 workitems and exactly 2 waves.
+; CHECK-LABEL: {{^}}empty_workitems_exactly_256_waves_exactly_2:
+; CHECK: SGPRBlocks: 12
+; CHECK: VGPRBlocks: 21
+; CHECK: NumSGPRsForWavesPerEU: 102
+; CHECK: NumVGPRsForWavesPerEU: 85
+define amdgpu_kernel void @empty_workitems_exactly_256_waves_exactly_2() #10 {
+entry:
+  ret void
+}
+attributes #10 = {"amdgpu-flat-work-group-size"="256,256" "amdgpu-waves-per-eu"="2,2"}