MIPS: math-emu: Mark fall throughs in switch statements with a comment

Mark intentional fall throughs in switch statements with a consistent
comment.

In most of the cases, a new comment line containing text "fall through"
is inserted. In some of the cases, existing comment contained a variation
of the text "fall through" (for example, "FALL THROUGH" or "drop through").
In such cases, the existing comment is modified to contain "fall through".
Lastly, in two cases, code segments were described in comments as "fall
througs", but were in reality "breaks out" of switch statement. In such
cases, existing comments are accordingly modified.

Apart from making code easier to follow and debug, this change enables
some static code analysers to interpret newly inserted comments as their
annotations (and, therefore, not issue warnings of type "fall through in
switch statement", which is desireable, since marked fallthroughs are
intentional).

Signed-off-by: Aleksandar Markovic <aleksandar.markovic@mips.com>
Cc: Douglas Leung <douglas.leung@mips.com>
Cc: Goran Ferenc <goran.ferenc@mips.com>
Cc: James Hogan <james.hogan@mips.com>
Cc: Maciej W. Rozycki <macro@mips.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Miodrag Dinic <miodrag.dinic@mips.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Petar Jovanovic <petar.jovanovic@mips.com>
Cc: Raghu Gandham <raghu.gandham@mips.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17588/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/math-emu/cp1emu.c

@@ -451,7 +451,7 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 					regs->cp0_epc + dec_insn.pc_inc +
 					dec_insn.next_pc_inc;
 			}
-			/* Fall through */
+			/* fall through */
 		case jr_op:
 			/* For R6, JR already emulated in jalr_op */
 			if (NO_R6EMU && insn.r_format.func == jr_op)
@@ -471,10 +471,11 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 			regs->regs[31] = regs->cp0_epc +
 				dec_insn.pc_inc +
 				dec_insn.next_pc_inc;
-			/* Fall through */
+			/* fall through */
 		case bltzl_op:
 			if (NO_R6EMU)
 				break;
+			/* fall through */
 		case bltz_op:
 			if ((long)regs->regs[insn.i_format.rs] < 0)
 				*contpc = regs->cp0_epc +
@@ -494,10 +495,11 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 			regs->regs[31] = regs->cp0_epc +
 				dec_insn.pc_inc +
 				dec_insn.next_pc_inc;
-			/* Fall through */
+			/* fall through */
 		case bgezl_op:
 			if (NO_R6EMU)
 				break;
+			/* fall through */
 		case bgez_op:
 			if ((long)regs->regs[insn.i_format.rs] >= 0)
 				*contpc = regs->cp0_epc +
@@ -512,11 +514,12 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 		break;
 	case jalx_op:
 		set_isa16_mode(bit);
+		/* fall through */
 	case jal_op:
 		regs->regs[31] = regs->cp0_epc +
 			dec_insn.pc_inc +
 			dec_insn.next_pc_inc;
-		/* Fall through */
+		/* fall through */
 	case j_op:
 		*contpc = regs->cp0_epc + dec_insn.pc_inc;
 		*contpc >>= 28;
@@ -528,6 +531,7 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 	case beql_op:
 		if (NO_R6EMU)
 			break;
+		/* fall through */
 	case beq_op:
 		if (regs->regs[insn.i_format.rs] ==
 		    regs->regs[insn.i_format.rt])
@@ -542,6 +546,7 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 	case bnel_op:
 		if (NO_R6EMU)
 			break;
+		/* fall through */
 	case bne_op:
 		if (regs->regs[insn.i_format.rs] !=
 		    regs->regs[insn.i_format.rt])
@@ -556,6 +561,7 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 	case blezl_op:
 		if (!insn.i_format.rt && NO_R6EMU)
 			break;
+		/* fall through */
 	case blez_op:
 
 		/*
@@ -593,6 +599,7 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 	case bgtzl_op:
 		if (!insn.i_format.rt && NO_R6EMU)
 			break;
+		/* fall through */
 	case bgtz_op:
 		/*
 		 * Compact branches for R6 for the
@@ -729,7 +736,8 @@ int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
 
 			return 1;
 		}
-		/* R2/R6 compatible cop1 instruction. Fall through */
+		/* R2/R6 compatible cop1 instruction */
+		/* fall through */
 	case cop2_op:
 	case cop1x_op:
 		if (insn.i_format.rs == bc_op) {
@@ -1221,14 +1229,14 @@ emul:
 			case bcfl_op:
 				if (cpu_has_mips_2_3_4_5_r)
 					likely = 1;
-				/* Fall through */
+				/* fall through */
 			case bcf_op:
 				cond = !cond;
 				break;
 			case bctl_op:
 				if (cpu_has_mips_2_3_4_5_r)
 					likely = 1;
-				/* Fall through */
+				/* fall through */
 			case bct_op:
 				break;
 			}

arch/mips/math-emu/dp_add.c

@@ -104,8 +104,7 @@ union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
-
-		/* FALL THROUGH */
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;

arch/mips/math-emu/dp_div.c

@@ -103,6 +103,7 @@ union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;

arch/mips/math-emu/dp_fmax.c

@@ -96,6 +96,7 @@ union ieee754dp ieee754dp_fmax(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;
@@ -224,6 +225,7 @@ union ieee754dp ieee754dp_fmaxa(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;

arch/mips/math-emu/dp_fmin.c

@@ -96,6 +96,7 @@ union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;
@@ -224,6 +225,7 @@ union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;

arch/mips/math-emu/dp_maddf.c

@@ -157,6 +157,7 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x,
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		if (zc == IEEE754_CLASS_INF)
@@ -173,7 +174,7 @@ static union ieee754dp _dp_maddf(union ieee754dp z, union ieee754dp x,
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
 		if (zc == IEEE754_CLASS_INF)
 			return ieee754dp_inf(zs);
-		/* fall through to real computations */
+		/* continue to real computations */
 	}
 
 	/* Finally get to do some computation */

arch/mips/math-emu/dp_mul.c

@@ -101,6 +101,7 @@ union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		DPDNORMY;

arch/mips/math-emu/dp_sqrt.c

@@ -142,7 +142,7 @@ union ieee754dp ieee754dp_sqrt(union ieee754dp x)
 		switch (oldcsr.rm) {
 		case FPU_CSR_RU:
 			y.bits += 1;
-			/* drop through */
+			/* fall through */
 		case FPU_CSR_RN:
 			t.bits += 1;
 			break;

arch/mips/math-emu/dp_sub.c

@@ -106,7 +106,7 @@ union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		DPDNORMX;
-		/* FALL THROUGH */
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		/* normalize ym,ye */

arch/mips/math-emu/sp_add.c

@@ -104,8 +104,7 @@ union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
-
-		/* FALL THROUGH */
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;

arch/mips/math-emu/sp_div.c

@@ -103,6 +103,7 @@ union ieee754sp ieee754sp_div(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;

arch/mips/math-emu/sp_fdp.c

@@ -46,7 +46,8 @@ union ieee754sp ieee754sp_fdp(union ieee754dp x)
 	case IEEE754_CLASS_SNAN:
 		x = ieee754dp_nanxcpt(x);
 		EXPLODEXDP;
-		/* Fall through.  */
+		/* fall through */
+
 	case IEEE754_CLASS_QNAN:
 		y = ieee754sp_nan_fdp(xs, xm);
 		if (!ieee754_csr.nan2008) {

arch/mips/math-emu/sp_fmax.c

@@ -96,6 +96,7 @@ union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;
@@ -224,6 +225,7 @@ union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;

arch/mips/math-emu/sp_fmin.c

@@ -96,6 +96,7 @@ union ieee754sp ieee754sp_fmin(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;
@@ -224,6 +225,7 @@ union ieee754sp ieee754sp_fmina(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;

arch/mips/math-emu/sp_maddf.c

@@ -126,6 +126,7 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x,
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		if (zc == IEEE754_CLASS_INF)
@@ -142,7 +143,7 @@ static union ieee754sp _sp_maddf(union ieee754sp z, union ieee754sp x,
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
 		if (zc == IEEE754_CLASS_INF)
 			return ieee754sp_inf(zs);
-		/* fall through to real computations */
+		/* continue to real computations */
 	}
 
 	/* Finally get to do some computation */

arch/mips/math-emu/sp_mul.c

@@ -101,6 +101,7 @@ union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;

arch/mips/math-emu/sp_sub.c

@@ -106,6 +106,7 @@ union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y)
 
 	case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
 		SPDNORMX;
+		/* fall through */
 
 	case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
 		SPDNORMY;