Author: tstellar Date: Wed May 24 09:08:01 2017 New Revision: 303746 URL: http://llvm.org/viewvc/llvm-project?rev=303746&view=rev Log: Merging r302416:
------------------------------------------------------------------------ r302416 | mstorsjo | 2017-05-08 06:26:24 -0400 (Mon, 08 May 2017) | 19 lines [ARM] Clear the constant pool cache on explicit .ltorg directives Multiple ldr pseudoinstructions with the same constant value will reuse the same constant pool entry. However, if the constant pool is explicitly flushed with a .ltorg directive, we should not try to reference constants in the previous pool any longer, since they may be out of range. This fixes assembling hand-written assembler source which repeatedly loads the same constant value, across a binary size larger than the pc-relative fixup range for ldr instructions (4096 bytes). Such assembler source already uses explicit .ltorg instructions to emit constant pools with regular intervals. However if we try to reuse constants emitted in earlier pools, they end up out of range. This makes the output of the testcase match what binutils gas does (prior to this patch, it would fail to assemble). Differential Revision: https://reviews.llvm.org/D32847 ------------------------------------------------------------------------ Added: llvm/branches/release_40/test/MC/ARM/ltorg-range.s Modified: llvm/branches/release_40/include/llvm/MC/ConstantPools.h llvm/branches/release_40/lib/MC/ConstantPools.cpp llvm/branches/release_40/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp Modified: llvm/branches/release_40/include/llvm/MC/ConstantPools.h URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_40/include/llvm/MC/ConstantPools.h?rev=303746&r1=303745&r2=303746&view=diff ============================================================================== --- llvm/branches/release_40/include/llvm/MC/ConstantPools.h (original) +++ llvm/branches/release_40/include/llvm/MC/ConstantPools.h Wed May 24 09:08:01 2017 @@ -60,6 +60,8 @@ public: // Return true if the constant pool is empty bool empty(); + + void clearCache(); }; class AssemblerConstantPools { @@ -83,6 +85,7 @@ class AssemblerConstantPools { public: void emitAll(MCStreamer &Streamer); void emitForCurrentSection(MCStreamer &Streamer); + void clearCacheForCurrentSection(MCStreamer &Streamer); const MCExpr *addEntry(MCStreamer &Streamer, const MCExpr *Expr, unsigned Size, SMLoc Loc); Modified: llvm/branches/release_40/lib/MC/ConstantPools.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_40/lib/MC/ConstantPools.cpp?rev=303746&r1=303745&r2=303746&view=diff ============================================================================== --- llvm/branches/release_40/lib/MC/ConstantPools.cpp (original) +++ llvm/branches/release_40/lib/MC/ConstantPools.cpp Wed May 24 09:08:01 2017 @@ -54,6 +54,10 @@ const MCExpr *ConstantPool::addEntry(con bool ConstantPool::empty() { return Entries.empty(); } +void ConstantPool::clearCache() { + CachedEntries.clear(); +} + // // AssemblerConstantPools implementation // @@ -95,6 +99,13 @@ void AssemblerConstantPools::emitForCurr } } +void AssemblerConstantPools::clearCacheForCurrentSection(MCStreamer &Streamer) { + MCSection *Section = Streamer.getCurrentSectionOnly(); + if (ConstantPool *CP = getConstantPool(Section)) { + CP->clearCache(); + } +} + const MCExpr *AssemblerConstantPools::addEntry(MCStreamer &Streamer, const MCExpr *Expr, unsigned Size, SMLoc Loc) { Modified: llvm/branches/release_40/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_40/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp?rev=303746&r1=303745&r2=303746&view=diff ============================================================================== --- llvm/branches/release_40/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp (original) +++ llvm/branches/release_40/lib/Target/ARM/MCTargetDesc/ARMTargetStreamer.cpp Wed May 24 09:08:01 2017 @@ -33,6 +33,7 @@ const MCExpr *ARMTargetStreamer::addCons void ARMTargetStreamer::emitCurrentConstantPool() { ConstantPools->emitForCurrentSection(Streamer); + ConstantPools->clearCacheForCurrentSection(Streamer); } // finish() - write out any non-empty assembler constant pools. Added: llvm/branches/release_40/test/MC/ARM/ltorg-range.s URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_40/test/MC/ARM/ltorg-range.s?rev=303746&view=auto ============================================================================== --- llvm/branches/release_40/test/MC/ARM/ltorg-range.s (added) +++ llvm/branches/release_40/test/MC/ARM/ltorg-range.s Wed May 24 09:08:01 2017 @@ -0,0 +1,27 @@ +@ RUN: llvm-mc -triple armv7-unknown-linux-gnueabi -filetype obj -o - %s \ +@ RUN: | llvm-objdump -d - | FileCheck %s + + ldr r0, =0x01020304 +@ CHECK: ldr + .ltorg +@ CHECK: 0x01020304 + ldr r0, =0x01020304 + ldr r0, =0x01020304 + ldr r0, =0x01020304 +@ CHECK: ldr +@ CHECK: ldr +@ CHECK: ldr + .ltorg +@ CHECK: 0x01020304 + .rep 1028 + .word 0 + .endr +@ CHECK: 0x00000000 + + ldr r0, =0x01020304 +@ CHECK: ldr + .ltorg +@ CHECK: 0x01020304 + .rep 1028 + .word 0 + .endr _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
