[clang] [Clang] [Sema] Fix bug in `_Complex float`+`int` arithmetic (PR #83063)

[via cfe-commits]

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+// RUN: %clang_cc1 %s -O0 -emit-llvm -triple x86_64-unknown-unknown -o - | FileCheck %s --check-prefix=X86
+
+// Check that for 'F _Complex + int' (F = real floating-point type), we emit an
+// implicit cast from 'int' to 'F', but NOT to 'F _Complex' (i.e. that we do
+// 'F _Complex + F', NOT 'F _Complex + F _Complex'), and likewise for -/*.
+
+float _Complex add_float_ci(float _Complex a, int b) {
+  // X86-LABEL: @add_float_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fadd float {{.*}}, [[I]]
+  // X86-NOT: fadd
+  return a + b;
+}
+
+float _Complex add_float_ic(int a, float _Complex b) {
+  // X86-LABEL: @add_float_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fadd float [[I]]
+  // X86-NOT: fadd
+  return a + b;
+}
+
+float _Complex sub_float_ci(float _Complex a, int b) {
+  // X86-LABEL: @sub_float_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fsub float {{.*}}, [[I]]
+  // X86-NOT: fsub
+  return a - b;
+}
+
+float _Complex sub_float_ic(int a, float _Complex b) {
+  // X86-LABEL: @sub_float_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fsub float [[I]]
+  // X86: fneg
+  // X86-NOT: fsub
+  return a - b;
+}
+
+float _Complex mul_float_ci(float _Complex a, int b) {
+  // X86-LABEL: @mul_float_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fmul float {{.*}}, [[I]]
+  // X86: fmul float {{.*}}, [[I]]
+  // X86-NOT: fmul
+  return a * b;
+}
+
+float _Complex mul_float_ic(int a, float _Complex b) {
+  // X86-LABEL: @mul_float_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fmul float [[I]]
+  // X86: fmul float [[I]]
+  // X86-NOT: fmul
+  return a * b;
+}
+
+float _Complex div_float_ci(float _Complex a, int b) {
+  // X86-LABEL: @div_float_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: fdiv float {{.*}}, [[I]]
+  // X86: fdiv float {{.*}}, [[I]]
+  // X86-NOT: @__divsc3
+  return a / b;
+}
+
+// There is no good way of doing this w/o converting the 'int' to a complex
+// number, so we expect complex division here.
+float _Complex div_float_ic(int a, float _Complex b) {
+  // X86-LABEL: @div_float_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to float
+  // X86: call {{.*}} @__divsc3(float {{.*}} [[I]], float noundef 0.{{0+}}e+00, float {{.*}}, float {{.*}})
+  return a / b;
+}
+
+double _Complex add_double_ci(double _Complex a, int b) {
+  // X86-LABEL: @add_double_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fadd double {{.*}}, [[I]]
+  // X86-NOT: fadd
+  return a + b;
+}
+
+double _Complex add_double_ic(int a, double _Complex b) {
+  // X86-LABEL: @add_double_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fadd double [[I]]
+  // X86-NOT: fadd
+  return a + b;
+}
+
+double _Complex sub_double_ci(double _Complex a, int b) {
+  // X86-LABEL: @sub_double_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fsub double {{.*}}, [[I]]
+  // X86-NOT: fsub
+  return a - b;
+}
+
+double _Complex sub_double_ic(int a, double _Complex b) {
+  // X86-LABEL: @sub_double_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fsub double [[I]]
+  // X86: fneg
+  // X86-NOT: fsub
+  return a - b;
+}
+
+double _Complex mul_double_ci(double _Complex a, int b) {
+  // X86-LABEL: @mul_double_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fmul double {{.*}}, [[I]]
+  // X86: fmul double {{.*}}, [[I]]
+  // X86-NOT: fmul
+  return a * b;
+}
+
+double _Complex mul_double_ic(int a, double _Complex b) {
+  // X86-LABEL: @mul_double_ic
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fmul double [[I]]
+  // X86: fmul double [[I]]
+  // X86-NOT: fmul
+  return a * b;
+}
+
+double _Complex div_double_ci(double _Complex a, int b) {
+  // X86-LABEL: @div_double_ci
+  // X86: [[I:%.*]] = sitofp i32 {{%.*}} to double
+  // X86: fdiv double {{.*}}, [[I]]
+  // X86: fdiv double {{.*}}, [[I]]
+  // X86-NOT: @__divdc3
----------------
Sirraide wrote:

Hmm, the only option I can think of is making sure we don’t have any other `fdiv`s and no `call`s at all? It’s not great, but it’s something. Should I update this test to do something in that vein, or do you think it’s good enough as-is?

https://github.com/llvm/llvm-project/pull/83063