[llvm] [X86] Respect code models more when determining if a global reference can fit in 32 bits (PR #75386)

[Reid Kleckner via llvm-commits]

================
@@ -96,12 +97,67 @@ define dso_local ptr @lea_static_data() #0 {
 ; LARGE-SMALL-DATA-PIC-NEXT:    leaq .L0$pb(%rip), %rax
 ; LARGE-SMALL-DATA-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
 ; LARGE-SMALL-DATA-PIC-NEXT:    addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT:    movabsq $static_data at GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT:    movl $static_data at GOTOFF, %eax
 ; LARGE-SMALL-DATA-PIC-NEXT:    addq %rcx, %rax
 ; LARGE-SMALL-DATA-PIC-NEXT:    retq
   ret ptr @static_data
 }
 
+define dso_local ptr @lea_static_data_alias() #0 {
+; SMALL-STATIC-LABEL: lea_static_data_alias:
+; SMALL-STATIC:       # %bb.0:
+; SMALL-STATIC-NEXT:    movl $static_data_alias, %eax
+; SMALL-STATIC-NEXT:    retq
+;
+; MEDIUM-STATIC-LABEL: lea_static_data_alias:
+; MEDIUM-STATIC:       # %bb.0:
+; MEDIUM-STATIC-NEXT:    movabsq $static_data_alias, %rax
+; MEDIUM-STATIC-NEXT:    retq
+;
+; LARGE-STATIC-LABEL: lea_static_data_alias:
+; LARGE-STATIC:       # %bb.0:
+; LARGE-STATIC-NEXT:    movabsq $static_data_alias, %rax
+; LARGE-STATIC-NEXT:    retq
+;
+; SMALL-PIC-LABEL: lea_static_data_alias:
+; SMALL-PIC:       # %bb.0:
+; SMALL-PIC-NEXT:    leaq static_data_alias(%rip), %rax
+; SMALL-PIC-NEXT:    retq
+;
+; MEDIUM-SMALL-DATA-PIC-LABEL: lea_static_data_alias:
+; MEDIUM-SMALL-DATA-PIC:       # %bb.0:
+; MEDIUM-SMALL-DATA-PIC-NEXT:    leaq static_data_alias(%rip), %rax
+; MEDIUM-SMALL-DATA-PIC-NEXT:    retq
+;
+; MEDIUM-PIC-LABEL: lea_static_data_alias:
+; MEDIUM-PIC:       # %bb.0:
+; MEDIUM-PIC-NEXT:    leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
+; MEDIUM-PIC-NEXT:    movabsq $static_data_alias at GOTOFF, %rax
+; MEDIUM-PIC-NEXT:    addq %rcx, %rax
+; MEDIUM-PIC-NEXT:    retq
+;
+; LARGE-PIC-LABEL: lea_static_data_alias:
+; LARGE-PIC:       # %bb.0:
+; LARGE-PIC-NEXT:  .L1$pb:
+; LARGE-PIC-NEXT:    leaq .L1$pb(%rip), %rax
+; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
----------------
rnk wrote:

The large PIC code model is awful. Is there really no way to express `$static_data_alias - .L1$pb` with a static relocation? That would avoid the need for the second add and i64 materialization.

https://github.com/llvm/llvm-project/pull/75386