The JAL in Long Branches cannot be relaxed further

Author: lenary

llvm/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp

@@ -664,13 +664,15 @@ uint64_t RISCVMCCodeEmitter::getImmOpValue(const MCInst &MI, unsigned OpNo,
       AsmRelaxToLinkerRelaxableWithFeature(RISCV::FeatureVendorXqcilb);
     } else if (MIFrm == RISCVII::InstFormatB) {
       FixupKind = RISCV::fixup_riscv_branch;
-      AsmRelaxToLinkerRelaxable();
+      // This might be assembler relaxed to `b<cc>; jal` but we cannot relax
+      // the `jal` again in the assembler.
     } else if (MIFrm == RISCVII::InstFormatCJ) {
       FixupKind = RISCV::fixup_riscv_rvc_jump;
       AsmRelaxToLinkerRelaxableWithFeature(RISCV::FeatureVendorXqcilb);
     } else if (MIFrm == RISCVII::InstFormatCB) {
       FixupKind = RISCV::fixup_riscv_rvc_branch;
-      AsmRelaxToLinkerRelaxable();
+      // This might be assembler relaxed to `b<cc>; jal` but we cannot relax
+      // the `jal` again in the assembler.
     } else if (MIFrm == RISCVII::InstFormatCI) {
       FixupKind = RISCV::fixup_riscv_rvc_imm;
     } else if (MIFrm == RISCVII::InstFormatI) {

llvm/test/MC/RISCV/align.s

@@ -137,18 +137,14 @@ data2:
 
 ## Branches crossing the linker-relaxable R_RISCV_ALIGN need relocations.
 # RELAX-RELOC:      .rela.text3 {
-# RELAX-RELOC-NEXT:    0x0  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# RELAX-RELOC-NEXT:    0x4  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# RELAX-RELOC-NEXT:    0x8  R_RISCV_ALIGN - 0x4
-# RELAX-RELOC-NEXT:    0xC  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# RELAX-RELOC-NEXT:    0x10 R_RISCV_BRANCH .Ltmp[[#]] 0x0
+# RELAX-RELOC-NEXT:    0x4 R_RISCV_BRANCH .Ltmp[[#]] 0x0
+# RELAX-RELOC-NEXT:    0x8 R_RISCV_ALIGN - 0x4
+# RELAX-RELOC-NEXT:    0xC R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT: }
 # C-OR-ZCA-EXT-RELAX-RELOC:      .rela.text3 {
-# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x0  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x4  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x8  R_RISCV_ALIGN - 0x4
-# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0xC  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x10 R_RISCV_BRANCH .Ltmp[[#]] 0x0
+# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x4 R_RISCV_BRANCH .Ltmp[[#]] 0x0
+# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0x8 R_RISCV_ALIGN - 0x4
+# C-OR-ZCA-EXT-RELAX-RELOC-NEXT:    0xC R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # C-OR-ZCA-EXT-RELAX-RELOC-NEXT: }
 	.section .text3, "ax"
 	bnez t1, 1f
@@ -165,11 +161,9 @@ data2:
 # RELAX-RELOC:      .rela.text3a {
 # RELAX-RELOC-NEXT:    0x0  R_RISCV_CALL_PLT foo 0x0
 # RELAX-RELOC-NEXT:    0x0  R_RISCV_RELAX - 0x0
-# RELAX-RELOC-NEXT:    0x8  R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT:    0xC  R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT:    0x10 R_RISCV_ALIGN - 0x4
 # RELAX-RELOC-NEXT:    0x14 R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# RELAX-RELOC-NEXT:    0x18 R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT: }
 .section .text3a, "ax"
 call foo
@@ -183,11 +177,9 @@ bnez t1, 2b
 
 ## .text3 with a call at the end
 # RELAX-RELOC:      .rela.text3b {
-# RELAX-RELOC-NEXT:    0x0  R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT:    0x4  R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT:    0x8  R_RISCV_ALIGN - 0x4
 # RELAX-RELOC-NEXT:    0xC  R_RISCV_BRANCH .Ltmp[[#]] 0x0
-# RELAX-RELOC-NEXT:    0x10 R_RISCV_BRANCH .Ltmp[[#]] 0x0
 # RELAX-RELOC-NEXT:    0x14 R_RISCV_CALL_PLT foo 0x0
 # RELAX-RELOC-NEXT:    0x14 R_RISCV_RELAX - 0x0
 # RELAX-RELOC-NEXT: }