[Transforms] Add pre-commit tests (NFC)

Author: AZero13

llvm/test/Transforms/InstCombine/cos-1.ll

@@ -17,6 +17,11 @@ declare float @llvm.sin.f32(float)
 declare double @tan(double)
 declare fp128 @tanl(fp128)
 
+declare double @fabs(double)
+declare double @llvm.fabs.f64(double)
+declare float @fabsf(float)
+declare float @llvm.fabs.f32(float)
+
 ; cos(-x) -> cos(x);
 
 define double @cos_negated_arg(double %x) {
@@ -100,6 +105,41 @@ define float @cosf_unary_negated_arg_FMF(float %x) {
   ret float %r
 }
 
+; cos(fabs(x)) -> cos(x)
+
+define double @cos_unary_fabs_arg(double %x) {
+; ANY-LABEL: @cos_unary_fabs_arg(
+; ANY-NEXT:    [[FABS:%.*]] = tail call double @llvm.fabs.f64(double [[X:%.*]])
+; ANY-NEXT:    [[R:%.*]] = call double @cos(double [[FABS]])
+; ANY-NEXT:    ret double [[R]]
+;
+  %fabs = tail call double @llvm.fabs.f64(double %x)
+  %r = call double @cos(double %fabs)
+  ret double %r
+}
+
+define float @cosf_unary_fabs_arg(float %x) {
+; ANY-LABEL: @cosf_unary_fabs_arg(
+; ANY-NEXT:    [[FABS:%.*]] = tail call float @llvm.fabs.f32(float [[X:%.*]])
+; ANY-NEXT:    [[R:%.*]] = call float @cosf(float [[FABS]])
+; ANY-NEXT:    ret float [[R]]
+;
+  %fabs = tail call float @llvm.fabs.f32(float %x)
+  %r = call float @cosf(float %fabs)
+  ret float %r
+}
+
+define float @cosf_unary_fabs_arg_FMF(float %x) {
+; ANY-LABEL: @cosf_unary_fabs_arg_FMF(
+; ANY-NEXT:    [[FABS:%.*]] = tail call float @llvm.fabs.f32(float [[X:%.*]])
+; ANY-NEXT:    [[R:%.*]] = call reassoc nnan float @cosf(float [[FABS]])
+; ANY-NEXT:    ret float [[R]]
+;
+  %fabs = tail call float @llvm.fabs.f32(float %x)
+  %r = call nnan reassoc float @cosf(float %fabs)
+  ret float %r
+}
+
 ; sin(-x) -> -sin(x);
 
 define double @sin_negated_arg(double %x) {