commit 17c0c4e7424187c50c3189566aa3432cee7cdc9a
author Volodymyr Turanskyy <volodymyr.turanskyy@arm.com> Wed Jul 04 16:11:15 2018 +0000
committer Volodymyr Turanskyy <volodymyr.turanskyy@arm.com> Wed Jul 04 16:11:15 2018 +0000
tree cfa930e83ce5aad5e1943d33277b74cbf15e7aaf
parent eaececf5e0c4c566838cf2bada8599e6346e59e7

[ARM] [Assembler] Support negative immediates: cover few missing cases

Support for negative immediates was implemented in
https://reviews.llvm.org/rL298380, however few instruction options were missing.

This change adds negative immediates support and respective tests
for the following:

ADD
ADDS
ADDS.W
AND.W
ANDS
BIC.W
BICS
BICS.W
SUB
SUBS
SUBS.W

Differential Revision: https://reviews.llvm.org/D48649

llvm-svn: 336286

llvm/lib/Target/ARM/ARMInstrThumb2.td

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb2.td b/llvm/lib/Target/ARM/ARMInstrThumb2.td
index c9dd01b..034cb1d 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb2.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb2.td
@@ -2104,6 +2104,12 @@
                  (t2ADDri GPRnopc:$rd, GPRnopc:$rn, t2_so_imm_neg:$imm, pred:$p, s_cc_out:$s)>;
 def : t2InstSubst<"subw${p} $rd, $rn, $imm",
                  (t2ADDri12 GPRnopc:$rd, GPR:$rn, t2_so_imm_neg:$imm, pred:$p)>;
+def : t2InstSubst<"subw${p} $Rd, $Rn, $imm",
+                 (t2ADDri12 GPRnopc:$Rd, GPR:$Rn, imm0_4095_neg:$imm, pred:$p)>;
+def : t2InstSubst<"sub${s}${p} $rd, $rn, $imm",
+                 (t2ADDri GPRnopc:$rd, GPRnopc:$rn, t2_so_imm_neg:$imm, pred:$p, s_cc_out:$s)>;
+def : t2InstSubst<"sub${p} $rd, $rn, $imm",
+                 (t2ADDri12 GPRnopc:$rd, GPR:$rn, t2_so_imm_neg:$imm, pred:$p)>;
 // RSB
 defm t2RSB  : T2I_rbin_irs  <0b1110, "rsb", sub>;
 
@@ -4731,12 +4737,24 @@
 def : t2InstSubst<"bic${s}${p} $Rdn, $imm",
                   (t2ANDri rGPR:$Rdn, rGPR:$Rdn, t2_so_imm_not:$imm,
                            pred:$p, cc_out:$s)>;
+def : t2InstSubst<"bic${s}${p}.w $Rd, $Rn, $imm",
+                  (t2ANDri rGPR:$Rd, rGPR:$Rn, t2_so_imm_not:$imm,
+                           pred:$p, cc_out:$s)>;
+def : t2InstSubst<"bic${s}${p}.w $Rdn, $imm",
+                  (t2ANDri rGPR:$Rdn, rGPR:$Rdn, t2_so_imm_not:$imm,
+                           pred:$p, cc_out:$s)>;
 def : t2InstSubst<"and${s}${p} $Rd, $Rn, $imm",
                   (t2BICri rGPR:$Rd, rGPR:$Rn, t2_so_imm_not:$imm,
                            pred:$p, cc_out:$s)>;
 def : t2InstSubst<"and${s}${p} $Rdn, $imm",
                   (t2BICri rGPR:$Rdn, rGPR:$Rdn, t2_so_imm_not:$imm,
                            pred:$p, cc_out:$s)>;
+def : t2InstSubst<"and${s}${p}.w $Rd, $Rn, $imm",
+                  (t2BICri rGPR:$Rd, rGPR:$Rn, t2_so_imm_not:$imm,
+                           pred:$p, cc_out:$s)>;
+def : t2InstSubst<"and${s}${p}.w $Rdn, $imm",
+                  (t2BICri rGPR:$Rdn, rGPR:$Rdn, t2_so_imm_not:$imm,
+                           pred:$p, cc_out:$s)>;
 // And ORR <--> ORN
 def : t2InstSubst<"orn${s}${p} $Rd, $Rn, $imm",
                   (t2ORRri rGPR:$Rd, rGPR:$Rn, t2_so_imm_not:$imm,

llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index df2e7ff..318bfe9 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -1030,7 +1030,12 @@
     if (!isImm()) return false;
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
     if (!CE) return false;
-    int64_t Value = -CE->getValue();
+    // isImm0_4095Neg is used with 32-bit immediates only.
+    // 32-bit immediates are zero extended to 64-bit when parsed,
+    // thus simple -CE->getValue() results in a big negative number,
+    // not a small positive number as intended
+    if ((CE->getValue() >> 32) > 0) return false;
+    uint32_t Value = -static_cast<uint32_t>(CE->getValue());
     return Value > 0 && Value < 4096;
   }
 
@@ -2242,7 +2247,7 @@
     // The operand is actually an imm0_4095, but we have its
     // negation in the assembly source, so twiddle it here.
     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(getImm());
-    Inst.addOperand(MCOperand::createImm(-CE->getValue()));
+    Inst.addOperand(MCOperand::createImm(-(uint32_t)CE->getValue()));
   }
 
   void addUnsignedOffset_b8s2Operands(MCInst &Inst, unsigned N) const {