Subzero: address mode opt: Transform *(reg+const) into [reg+const].

tests_lit/llvm2ice_tests/address-mode-opt.ll

+; This file checks support for address mode optimization.
+
+; RUN: %llvm2ice -O2 --verbose none %s | FileCheck %s
+; RUN: %llvm2ice -O2 --verbose none %s \
+; RUN:               | llvm-mc -arch=x86 -x86-asm-syntax=intel -filetype=obj
+; RUN: %llvm2ice --verbose none %s | FileCheck --check-prefix=ERRORS %s
+
+define float @load_arg_plus_200000(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr.int = add i32 %arg.int, 200000
+  %addr.ptr = inttoptr i32 %addr.int to float*
+  %addr.load = load float* %addr.ptr, align 4
+  ret float %addr.load
+; CHECK-LABEL: load_arg_plus_200000:
+; CHECK: movss xmm0, dword ptr [eax+200000]
+}
+
+define float @load_200000_plus_arg(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr.int = add i32 200000, %arg.int
+  %addr.ptr = inttoptr i32 %addr.int to float*
+  %addr.load = load float* %addr.ptr, align 4
+  ret float %addr.load
+; CHECK-LABEL: load_200000_plus_arg:
+; CHECK: movss xmm0, dword ptr [eax+200000]
+}
+
+define float @load_arg_minus_200000(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr.int = sub i32 %arg.int, 200000
+  %addr.ptr = inttoptr i32 %addr.int to float*
+  %addr.load = load float* %addr.ptr, align 4
+  ret float %addr.load
+; CHECK-LABEL: load_arg_minus_200000:
+; CHECK: movss xmm0, dword ptr [eax-200000]
+}
+
+define float @load_200000_minus_arg(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr.int = sub i32 200000, %arg.int
+  %addr.ptr = inttoptr i32 %addr.int to float*
+  %addr.load = load float* %addr.ptr, align 4
+  ret float %addr.load
+; CHECK-LABEL: load_200000_minus_arg:
+; CHECK: movss xmm0, dword ptr [eax]
+}
+
+define float @address_mode_opt_chaining(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr1.int = add i32 12, %arg.int
+  %addr2.int = sub i32 %addr1.int, 4
+  %addr2.ptr = inttoptr i32 %addr2.int to float*
+  %addr2.load = load float* %addr2.ptr, align 4
+  ret float %addr2.load
+; CHECK-LABEL: address_mode_opt_chaining:
+; CHECK: movss xmm0, dword ptr [eax+8]
+}
+
+; ERRORS-NOT: ICE translation error