| # RUN: llc -mtriple=aarch64 -o - %s \ |
| # RUN: -run-pass register-coalescer | FileCheck %s |
| |
| # In this test case, the 32-bit copy implements a 32 to 64 bit zero extension |
| # and relies on the upper 32 bits being zeroed. |
| # Coalescing to the result of the 64-bit load meant overwriting |
| # the upper 32 bits incorrectly when the loaded byte was negative. |
| |
| --- | |
| @c = local_unnamed_addr global i8 -1, align 4 |
| |
| define i64 @bug_e(i32 %i32) local_unnamed_addr { |
| ret i64 0 |
| } |
| ... |
| --- |
| name: bug_e |
| tracksRegLiveness: true |
| body: | |
| bb.0: |
| liveins: $w0 |
| |
| %1:gpr32 = COPY $w0 |
| %2:gpr64common = ADRP target-flags(aarch64-page) @c |
| %3:gpr64 = LDRSBXui %2, target-flags(aarch64-pageoff, aarch64-nc) @c :: (dereferenceable load (s8) from @c, align 4) |
| %0:gpr32 = COPY %3.sub_32 |
| ; CHECK: {{.*}}.sub_32:gpr64 = COPY {{.*}}.sub_32 |
| STRBBui %1, %2, target-flags(aarch64-pageoff, aarch64-nc) @c :: (store (s8) into @c, align 4) |
| %8:gpr64all = SUBREG_TO_REG 0, %0, %subreg.sub_32 |
| $x0 = COPY %8 |
| ; CHECK: $x0 = COPY |
| RET_ReallyLR implicit $x0 |
| ... |